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BiologicalJoumal of the Linnean Society (1995), 56: 79-1 19. With I figure
ï P&
b@@'fie
Pitcairn Islands: biogeography, ecology and prehistory
/Edited by T. G. Benton and T. Spencer
The flora of the Pitcairn Islands: a review
I
J. FLORENCE
I
Centre ORSTOM de Tahiti, BP 529, Papeete, Tahiti, Polynhsie Française
S. WALDREN
Trinity College Botanic Garden, Palmerston Park, Dartry, Dublin 6, Ireland
A. J. CHEPSTOW-LUSTY
Defiartment of Plant Sciences, University of Cambridge, Downing Street, Cambridge
CB2 3EA
The vascular plant flora of the Pitcairn Islands, south-central Pacific Ocean, is described
based on extensive new collections made in 1991 and previously published records. Two
vascular plants occur on Ducie Atoll; one (Pemphb acidula) is a new record. Sixty-three native
vascular plants occur on Henderson, of which nine are endemic; Canavalia rosea, Operculina
turpethum, Psilotum nudum and Solanum americanum are new records for the island. Oeno Atoll
has 16 native vascular plants; the single endemic (Bidens hendersonensb var. oenoensis) was not
found in 1991 despite careful searches. Triumjëtta procumbens was new for Oeno. Sixty-six
native vascular plants have now been recofded from Pitcairn Island, there are two endemic
fems and seven endemic angiosperms in this number. A number of non-native taxa were
new to Pitcairn. Some of the previously described taxa could not be found on Pitcaim,
probably because they are very rare and only a small amount of time was spent collecting
on Pitcaim. Many of the Pitcairn taxa are threatened by the spread of introduced species,
especially Syzygium jumbos.
O 1995 The Linnean Society of London
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ADDITIONAL KEY WORDS:-Pitcaim - Henderson - Oeno
biogeography - South Pacific - South East Polynesia
-
Ducie
-
flora
-
island
CONTENTS
Introduction . . . . . .
Generalcharacteristicsofthe flora .
Floristic list of vascular plants . .
Ducie Island . . . . . .
Henderson Island . . . . .
Oeno Island . . . . . .
Pitcaim Island . . . . . .
Acknowledgemexiti . . . .
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84
97
100
114
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010023133
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80
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J. FLORENCE ETAL.
References
. . . . . . . . . . . . . . . . . . .
Appendix 1: Taxonomic pollen notes of some of the endemic species and varieties of
Henderson Island . . . . . . . . . . . . . . . . .
Appendix 2: The lichens of Henderson Island and Oeno Atoll, a preliminary survey . .
114
114
117
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INTRODUCTION
Lying at the south eastern part of Polynesia, the Pitcairn Islands are remote
from the nearest archipelagos of French Polynesia: the Austral, Gambier and
Tuamotu groups. The Pitcairn Group is itself very diffuse; Ducie Atoll is
further from Pitcairn (c. 600 km) than Oeno Atoll is from the Gambier, the
nearest archipelago, c. 450 km distant. Remoteness, both within the group
and between the group and other archipelagos, is therefore a major factor
in determining the floristic spectrum and phytogeography.
Before describing the floristic findings of the expedition, some general
comments on the endemic and indigenous flora of the vascular plants are
given. The present flora is then described in relation to the expedition
findings, and to previous collections.
GENERAL CHARACTERISTICSN
OF THE. FLORA
-7
The Pitcairn Islands, together with the islands of French Polynesia and the
Cook Islands, belong to the phytogeographical area defined as the subprovince of east Polynesia in the Malesian region by van Balgooy (1971).
Tables 1-3 summarizes the presently known information about the indigenous
and endemic flora of the Pitcairn Group, together with that of the Gambier,
Austral and Tuamotu archipelagos. All data are extracted from ‘Nadeaud’, a
database held at OMTOM-Tahiti.
The most striking feature is the poor flora of Ducie Atoll. This can be
partly explained by extreme remoteness, Ducie is effectively the eastern-most
island of the Indo-Pacific biogeographic province. The flora of Easter Island
further to the east is essentially non-Polynesian, with a predominance of
American and Subantarctic elements, in addition to widespread Indo-Pacific
z
T ~ L 1.
E Floristic diversity of the Pitcairn Group in comparison with the Austral, Gambier
and Tuamotu archipelagos. Indigenous implies native to more than one island/archipelago,
endemic implies native to a single island/archipelago. The number of uncertain taxa are
given in parentheses
Island/
archipelago
Ducie
Henderson
Oeno
Pitcairn
Pitcairn group
Australs
Gambiers
Tuamotus
Indigenous
Endemic
Area Indigenous Indigenous vascular Endemic Endemic vascular
(km’)
ferns
angiosperms plants
ferns angiosperms plants Total
0.74
37.2
0.62
6.6
45.2
148
46
726
O
9
2
2 1 (1)
23 (1)
81
19
19
2
45 (3)
13
36(3)
63 (4)
121
53
76
2
54 (3)
15
57 (1)
86
202
72
89
O
O
O
2
2
15
9
O
O
9
1
7
17
72
8
4
O
9
1
9
19
87
8
4
2
63
16
66
105
289
80
95
FLORA OF THE PITCAIRN GROUP
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81
TABLE
2. Krìber similarity index (above diagonal) and number of common species (below
diagonal) for the Pitcairn Group, and the Austral, Gambier and Tuamotu archipelagos
Henderson
Oeno
Pitcairn
Australs
Gambiers
Tuamotus
Henderson
Oeno
Pitcairn
Australs
Gambiers
Tuamotus
*
56
*
48
26
6
15
13
15
*
53
54
52
*
50
59
35
40
31
22
53
52
54
GO
64
61
43
13
24
44
32
34
*
49
54
*
Total
species
54
15
57
202
72
89
TABLE
3. Dispersal mechanisms for native non-endemic taxa of
the Pitcairn Group (percentages of total flora in parentheses)
Dispersal mechanism
Ducie
Henderson
Oeno
Pitcairn
~~
Anemochory
Hydrochory
Active zoochory
Passive zoochory
O
2 (100)
O
O
11 (21)
16 (31)
14 (27)
11 (21)
2 (13)
5 (33)
1 (7)
7 (47)
21 (43)
11 (23)
10 (21)
6 (12)
Q
*\
d
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or pantropic strand species (Zizka, 1991). Ducie, in common with most atolls,
might be expected to have a poor flora because of the limited number of
ecological niches available, and because it is exposed to marine overwashing
during storms (Fosberg, 1991; Waldren, Florence & Chepstow-Lusty, 1995).
These factors will limit the range of species which can successfully establish
and compete with existing vegetation. The flora of Ducie was previously
reported by Rehder & Randall (1975), who recorded t wo widespread strand
species only.
Oeno Atoll also has a small native flora, but it is considerably more
diverse than that of Ducie. This might be explained by its proximity to
other islands which can act as a source of propagules. The flora of Oeno
has been previously described by St John & Philipson (1960). Like Ducie,
the flora consists mainly of common strand species, but it has one endemic
taxon, Bidens hendersonensis var. oeaoensis Sherff, a relative of the typical variety
from Henderson. Despite a careful search, we failed to locate this taxon.
The Tuamotu archipelago, consisting entirely of atolls, is floristically richer
than Oeno.
Henderson and Pitcairn both have a far greater number of native species
than the t wo atolls, and both islands contain a similar number of endemic
species (Table 1). Henderson Island, a raised atoll, has a total of 63 native
taxa, of which nine are endemic; the flora has been previously reported by
St John & Philipson (1962) and Fosberg et a l (1989). At approximately 30 m
above sea level, the raised plateau is not overwashed by sea water, and
vegetation development is far more complete and the flora more diverse
than on the atolls. This in turn has led to enhanced soil development (S.
Walden & L. Scally, unpublished data), and hence a much wider range of
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82
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J. FLORENCE ETAL.
habitat types than low atolls subject to periodic marine inundation. The
following nine taxa are endemic to Henderson:
Alyxia sp.
Bidens hendersonensis var. hendersonensis
Xylosnia suaveolens ssp. haroldii
Geniostoma hendersonensis
Myrsine hosakae
Peperomia hendersonensis
Ixora jbgrans
Santalum insulare var. hendersonense
Nesoluma st-johnianum.
4
Although the number of endemic taxa appears low for this part of
Polynesia (Florence, 1987), some of them are important from a biogeographical
point of view, with related taxa having a narrow or disjunct distribution in
the area. For example, Nesoluma is a Pacific genus with a disjunct distribution:
'Hawaii, Mangaia in the southern Cook Islands, the Austral and Society
groups, and Henderson. Henderson is also the extreme eastern limit for
Alyxia and Santalum is known further east only in Juan Fernandez. The other
genera are more widespread in the Indo-Pacific or even further afield, but
all have their most eastern limit on Henderson. Because of this, Henderson
is of great biogeographic interest, and may provide valuable insights into the
chorology and the mechanisms of dispersal of many taxa in the Pacific.
Pitcairn Island is a small volcanic island of relatively low elevation (to
about 330 m) but with a greater variety of habitats than a low coral island
(Florence, 1987; Waldren, Florence & Chepstow-Lusty, 1995), with 66 native
taxa; the flora was previously reported by St John (1987) with some notes
in Fosberg et al. (1989). The following 9 taxa are endemic to Pitcairn:
Bidens mathewsii
Glochidion sp.
Homalium taypnu
Abutilon pitcairnense
Myrsine sp. aff. niauensis
Peperomia pitcarinensis
Coprosma rapensis var. beneJica
Ctenitis cumingii
Angiopteris chauliodonta.
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Despite the slightly lower percentage of endemics than Henderson, Pitcairn
shows a number of interesting features: Bidens mathewsii is a relative of B.
hendersonensis, and Abutilon has relatives in the Gambier Islands and the
Marquesas. Coprosma is a Malesian-Pacific genus with the eastern limit at
Pitcairn, the typical variety is from Rapa. Glochidion has numerous related
species in the islands of eastern Polynesia (J. Florence, unpublished data).
Myrsine is a genus with many endemic species throughout the south Pacific,
but the Pitcairn species is insufficiently known; the same is true of Peperomia
pitcairnensis. However, the most interesting feature of Pitcairn is that t wo
endemic ferns occur on such a small island; both Ctenitis and Angiopteris
have relatives in French Polynesia.
FLORA. OF THE PITCAIRN GROUP
FLORISTIC LIST OF VASCULAR PLANTS
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83
The following lists of taxa are arranged alphabetically in the major taxonomic
groups: Dicotyledons, Monocotyledons, Gymnosperms and Pteridophytes.
Synonymy is given only for names different from previous papers on the
flora of the region, citations are given for synonyms in order to facilitate
comparison between all previous floristic accounts of the Pitcairn Group.
Short botanical descriptions are only given at the first occurrence of the
species. Voucher specimens are located at PAP, with duplicates at BISH,
BM, BRIT, CHR, DAV, E, K, L, MO, P, PTBG, STR, TCD, us, WELT;
WELTU.
The following abbreviations give the phytogeographical status:
t
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End: Endemic, here referring to the individual islands in the Pitcairn
Group,
Ind: Indigenous, a taxon that is considered native but not endemic,
Pol: Early Polynesian introduction, introduced prior to European contact,
Nat: Naturalised, a taxon deliberately introduced by man and now
established in a natural state,
Adv: Adventive, established taxa that were not deliberately introduced,
includes all weeds,
Cul: Cultivated, not naturalised.
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DUCIE ISLAND
Boraginaceae
Argusia argentea (L. f.) H. Heine
- Tournefortia argentea L. f, Rehder & Randall (1975: 18).
(In4
A compact tree, leaves greyish green, mainly at the end of branches, fragrant
small white flowers. Forms a monospecific forest (Waldren et al., 1995).
Brooke in Florence 11050.
Lythraceae
3
zy
Pemphis acidula J. R. & G. Forster
(In4
A small tree with hard red wood, small leaves and small white flowers. Very
rare. A new record and only the second woody species recorded from the
island. This species was not noted during the 1987 visit of Smithsonian
Expedition despite ‘careh1 searches’ (Fosberg et a l , 1989: 18), and may be
a recent colonist. Brooke in Florence 11057.
Rehder & Randall (1975) and Fosberg et al. (1989) reported earlier sitings
of a grass, probably Lepturus repens (G. Forster) R. Brown, and a vine,
possibly Nesogenes euphrasioides A. Gray or Triumjètta procumbens G. Forster,
but neither has been seen on the atoll since the Whitney Expedition in
1922.
84
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J. FLORENCE ETAL.
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HENDERSON ISLAND
Dicotyledonae
Aizoaceae
Sesuvium portulacastrum (L.) L.
(Ind.)
A succulent herb with pink flowers. Common along the southern cliffs, rare
on the North Beach cliffs. Florence, Chepstow-Lusty &' Waldren 10923, 10988.
Amaranthaceae
Achyranthes aspera var. pubescens (Moquin) C. Townsend
(Ind or Pol)
- Achyranthes aspera semu St John & Philipson (1962: 180).
A slender and more or less scandent suffrutescent herb. Differs from the
typical A. aspera by the presence of a very sparse pubescence on leaves and
details of the staminodial corona. Only one station on the plateau, probably
the same location as Tait 66, cf. St John & Philipson (1962: 180). The status
of this taxon is uncertain; however, its presence in the plateau forest and
absence from the vicinity of Polynesian habitation sites suggests that it may
be native. In the absence of a recent overview of the polymorphic A. aspera
in the Pacific, we follow Fosberg et al. (1989) in using this varietal name.
Brooke in Florence 11053; Florence, Chepstow-Lusty &' Waldren 10928.
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Apocynaceae
Alyxia sp.
(End)
- Alyxia stellata sensu St John & Philipson (1962: 192)
Clearly a new species, as indicated by Fosberg et al. (1989: 9); this will be
described in a separate publication. A relative of A. stellata from the South
Pacific, which has many forms on islands from the Society Islands to New
Caledonia; the Henderson species differs by its consistently 4-5-merous
verticillate leaves, more elongate cymes, larger flowers with glabrous calyx
lobes, and seeds with a more-deeply rugose coat. Found on the plateau in
the Pisonia forest, generally in sunny places, in tree-gaps or edges of former
trails. Locally frequent in hora thickets. Florence 10848, 10959; Florence,
Chepstow-Lusty &' Waldren 10887, 10895, 10918, 10927.
Araliaceae
Meryta brachypoda Harms
(Indl
Simple or few-branched, crushed leaves lightly fragrant. Only one sterile,
small population seen in Pisonia forest near the massively dissected limestone
inland from the North West Beach; fits the vegetative description of M.
brachypoda. Previously collected only by Tait in 1912. An interesting disjunct
distribution; found also in the Austral Islands. Florence, Chepstow-Lusty 6'
Waldren 1 1004.
z
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FLORA OF THE PITCAIRN GROUP
85
Asteraceae
Bidens hendersonensis var. hendersonensis Sherff
(End)
- Bidens hendersonensis var. subspathulata Sherff; St John & Philipson
(1962: 194) syn. nov. Type: St John & Fosberg 15173 BISH
With more specimens to hand and close observations of this species in the
field, it appears that the minor variations in shape and size of leaves and
details in achenes named at varietal rank by Sherff are not dependable
characters, and no others have been discerned to separate his two varieties.
A shrub or small tree, the crushed leaves lightly fragrant; capitula yellow,
slightly foetid, with 3-5 ligules. Common on the plateau in open or partshaded places. Florence 10817, 10958, 10980, 10997; Florence, Chepstow-Lusty
63 Waldren 10824, 10871, 10998.
t
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Senecio stokesii F. Brown
(In4
A very variable herb, simple or many-branched, the leaves varying greatly
according to the habitat; this variation apparently not under genetic control
(J. MacMin & S. Waldren, unpublished data). Capitula yellow to yelloworange, foetid. Common in many pZaces in the plateau forests, generally in
gaps or colonizing old trails. Also in dwarf coastal scrub communities, and
the scrub inland from the East Beach. Found also in the Austral Islands.
Florence 10957, 10965, 10977, 10995; Florence, Chepstow-Lusty €3 Waldren 10883,
10884, 10906, 10984.
Boraginaceae
Argusia argentea (L. f.) H. Heine
(14
- Tournefortia argentea L. f. Fosberg et al. (1989: 10)
- Messerschmidia argentea (L. f.) I. Johnston. St John & Philipson (1962:
193).
One of the commonest trees on the North and East Beaches, on coral gravel
or sand. Florence, Chepstow-Lusty ¿
Waldren
i?' 10924.
r
II
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Cordia subcordata Lamarck
(Pol)
A small tree with orange flowers. Probably a Polynesian introduction, used
as carving wood by Pitcairn islanders. Established in beach forest communities
on the North and East beaches, often with nespesia populnea. Florence 70821.
Heliotropium anomalum var. argenteum A. Gray
(14
- Heliotropium anomalum var. candidum St John. St John & Philipson
(1962: 192)
In beach-front communities, but also on coastal cliff tops. A repent prostrate
perennial herb, with small white fragrant flowers. The same variety occurs
in the Hawaiian Islands. Florence 10857, 10964; Florence 63 Waldren 10854;
Florence, Chepstow-Lusty €3 Waldren 10987.
86
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Brassicaceae
J. FLORENCE ETAL.
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Lepidium bidentatum Montin
(In4
An erect suffruticose herb, leaves are peppery to taste, flowers white. In
coastal rock crevices, ledges, and open stations on the plateau; locally
common. Florence 10968; Florence &' Waldren 10877; Florence, Chepstow-Lusty
&' Waldren 10905, 10920, 11006.
Capparaceae
Capparis cordifolia Lamarck
(Indl
- Capparis sandwichiana DC., Fosberg, Sachet & Stoddart (1983: 31)
An epilithic scandent shrub, night-flowering, the white flowers fading to pink
by the following afternoon. Local, on coastal dissected limestone, promontories
and on the top of the southern cliffs. Florence &' Waldren 70857; Florence,
Chepstow-Lusty €9 Waldren 1O9 12.
Convolvulaceae
zy
./
Ipomoea macrantha J. Roemer & J. A. Schultes
(14
- Ipomoea glaberrima Bojer. St John & Philipson (1962: 192)
A trailing and climbing vine, white flowers open late evening, fading by
mid-morning. Moderately common in coastal Argusia scrub. Florence 10876;
Florence, Chepstow-Lusty &' Waldren 10873.
Operculina turpethum (L.) S. Manso
(14
A trailing vine, old stems narrowly alate, young twigs and leaves densely
pubescent, flowers white. Very local at the southern end, with Capparis and
Cmsytha in open dissected limestones. First record of this species, known
from the old World tropics and Pacific Islands. Florence, Chepstow-Lusty €5'
Waldren 10909, 10989.
Euphorbiaceae
Chamaesyce sparrmannii (Boissier) Hurusawa
(In4
- Euphorbia sparrmannii Boissier, Fosberg et al. (1989: 6).
-Euphorbia ramosissima Hooker & Arnott non Loiseleur. St John &
Philipson (1962: 186).
A prostrate herb with milky juice, trailing branches and white involucral
glands. A relative of the shrubby C. atoto from other parts of the Pacific.
Common on coastal cliff tops, and in the dwarf shrub communities at the
southern end. Florence 10860; Florence €i
Waldren
?
1085.3, 10879, 11012.
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Glochidion pitcairnense (F. Brown) H. St John
(In4
A tree, on Henderson with drooping twigs, slightly bullate leaves, very small
yellowish green flowers, and green capsules with vermilion seeds that are
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FLORA OF THE PITCAIRN GROUP
87
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eaten by birds. The species is also found on Pitcairn and in the Gambier
Islands. Florence 10818; Florence, Chepstow-Lusty €3 Waldren 10825, 10900.
Flacourtiaceae
Xylosma suaveoleizs subsp. haroldii Sleumer
(End)
A dioecious small to large tree with hard, reddish wood. Male flowers slightly
fragrant, female green, fruit black at maturity. Common in Pisonia forest on
the plateau, and locally abundant on poorer soils (S. Waldren & L. Scally,
unpublished data). Florence 10868; Florence, Chepstow-Lus8 €3 Waldren 10827,
10869, 10870.
Goodeniaceae
Scaevola sericea Vahl
(Ind)
1Scaevola taccada var. tuamotuensis St John. St John & Philipson (1962:
194)
- Scaevola sericea var. tuamotuensis (St John) Fosberg. Fosberg et al.
(1989: 11)
A spreading shrub, flowers white to cream, fruits white. Common in sandy
coastal communities, and on cliff slopes. O n the plateau, found in Timonius
scrub towards the centre of the island. Florence 10864, 10867; Florence,
Chepstow-Lusty €3 Waldren 10882, 10911.
Hernandiaceae
Hernandia stokesii (F. Brown) Kubitzki
(In4
- Hernandia sonora sensu St John. St John & Philipson (1962: 181)
A small tree known only from the western pinnacled limestone, about 1 km
south-east of the North West Beach. Leaves not distinctly peltate in mature
trees, fruits purple-red at maturity. Has an interesting disjunction because it
is otherwise known only from Rapa, c. 1600 km to the west. Florence,
Chepstow-Lusty 6'
Waldren 1 1005, 11008.
Lauraceae
.I
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Cassytha jilformis L.
(Indl
A parasitic vine climbing over shrubs or sprawling in open places. Very
common in shrubby vegetation, and locally abundant on cliff slopes. Florence
10837.
Leguminosae
Caesa@inia bonduc (L.) Roxburgh
(In4
- Caesalpinia major sensu Fosberg et al. (1989: G), non (Medikus) Dandy
& Exell
A coarse prickly liana, distinct from C. major by persistent, conspicuous,
88
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z
J.FLORENCE ETAL.
compound stipules, and pods with t wo greyish seeds. Local in the north
part, mainly restricted to plateau forest close to the north beach; rare inland
from East Beach. Florence, Chepstow-Lusty G? Waldren 10835.
Canavalia rosea (Swartz) A.P. DC.
(Id
A trailing vine with pink flowers. Widespread on the seacoasts of the Tropics,
but this is the first record for Henderson. Only one location at the southern
end, near to the cliff edge in a dwarf scrub community, with Capparis,
Guettarda ,and Cassytha. Brooke in Florence 11052; Florence, Chepstow-Lusty &
Waldren I O9 14, 10986.
Senna glanddigera (St John) A. C. Smith
(In4
- Cassia glanddigera St John. St John & Philipson (1962: 181, fig. 8);
Fosberg et al. (1989: 6).
A small tree, simple or few-branched near the apex, flowers yellow; the
indehiscent legumes are brown to blackish. Restricted to the plateau forest
in the northern half, generally gregarious in small gaps and along old trails.
Large numbers of seedlings were often found under the shade of other trees,
it is possible that these may remain in a juvenile state for some time until
a gap opens in the canopy. Florence, Chepstow-Lusty & Waldren 10833.
1)
Loganiaceae
Geniostoma hendersonense H. St John
(End)
A shrub from the understorey of the Pisonia forest on the plateau. One of
the commoner endemic species. Flowers white, with an odour of urine; black
fruits, with orange-pink seeds. Florence 10836, 10838, 10996; Florence, ChepstowLusty &Y Waldren 10828, 11002.
Lythraceae
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Pemphis acidula J. R. & G. Forster
(Indl
Occurs on beachrock and low coastal limestone outcrops only; absent from
sandy areas. Florence 10973; Florence & Waldren 10856.
Malvaceae
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fiespesia populnea (L.) Solander ex Correa
(Ind, Pol?)
A tree probably introduced by Polynesians as elsewhere in Eastern Polynesia
(see Zizka, 1991), but fossil fruits have been found in pre-cultural deposits
on Henderson (M. Weisler, personal communication). Used for carving by
Pitcairn Islanders, and regularly harveste'd from the North and North West
Beaches. In beach forest communities and other coastal forests behind the
North and North West Beaches; absent from similar habitat at the East
Beach. Florence, Chepstow-Lusty 6'Waldren 10889.
zyx
zyxwvuts
FLORA OF THE PITCAIRN GROUP
Myrsinaceae
Myrsine hosakae H. St John
(End)
89
zyxw
A small functionally dioecious tree, with ramiflorous flowers, fruits eaten by
birds. Apparently uncommon, in closed Pisonia forest only on the plateau.
Florence 10840, 10978, 10979; Florence, Chepstow-Lusty €8 Waldren 10993.'
Myrtaceae
*J
Eugenia reinwardtiana (Blume) A.P. DC.
(Ind)
- Eugenia rargora Bentham. St John & Philipson (1962: 187); Fosberg
et al. (1989: 7).
A shrublet in the understorey of the plateau, also in open communities at
the edges of the plateau. Widespread throughout the island, but never really
abundant; commonest in the Timonius scrub in the centre of the island.
Obvious by its large, showy, red uniseeded fruits which are eaten by birds.
Florence 10819; Florence €8 Waldren 10850.
Nyctaginaceae
Boerhavia tetrandra G. Forster
(Indl
- Boerhavia dzfisa var. tetrandra (G. Forster) Heimerl. St John &
Philipson (1962: 181).
A trailing vine or herb with pink flowers, common in the herbaceous state
on coral sand, and cliff slopes. Florence 10859, 10966; Florence €8 Waldren
10852.
zyxwvut
zyxwvut
zy
Pisonia grandis R. Brown
(Indl
A soft-wooded medium to large tree, with brittle twigs. Flowering trees not
seen during our stay. The commonest tree on Henderson, forming dense
stands on the plateau (vegetative propagation very frequent). Varies greatly
in stature, from large (to 15 m) trees small bushy plants (to 1 m) in exposed
cliff top communities. No seedlings seen of this species. Brooke in Florence
11054; Florence €8 Waldren 11010.
I
r'
Piperaceae
Peperomia hendersonensis Yuncker
(End)
A succulent herb, stems erect with swollen nodes, dark green shiny leaves
with 'nerves impressed above. A relative of the complex centred on P.
rlzomboidea W. J. Hooker & Arnott from French Polynesia and the Cook
Islands. A common endemic herb in rock fissures and on the forest floor.
Florence 10841; Florence €8 Waldren 1107 1; Florence, Chepstow-Lusty 6'
Waldren
10890.
90
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zyxw
J. FLORENCE ETAL.
Pittosporaceae
Pittosporum aff. arborescens W. Rich ex A. Gray
(14
A prostrate sterile shrub, leaves a little carnose. Only one station found at
south end of the island, slightly north east of the South Point. The plant
could not be found in previous stations in the plateau forests, and at the
plateau margin near the North Beach. Identified as P. arborescens by St John
& Philipson (1962: 181); in the absence of fertile specimens, we regard this
determination as provisional. Florence, Chepstow-Lusty €8 Waldren 1O99 7.
Portulacaceae
zyx
z
zy
Portulaca lutea Solander ex Seemann
(14
A succulent perennial herb with a thick, fleshy stem-base; bright yellow
fragile flowers, leaves varying greatly in size depending on whether growing
in sheltered or salt-exposed locations. Common on the exposed plateau
margins with Sesuvium; occasional on the East Beach strandline. Florence
10862, 10967; Florence €5' Waldren 10878; Florence, Chepstow-Lusty CY Waldren
10913.
9
Rubiaceae
Cyclophyllum barbatum (G. Forster) N. Halle & Florence
(In4
- Canthium barbatum var. christianii, forma calcicola Fosberg. St John &
Philipson (1962: 193); Fosberg et al. (1989: 10).
In the absence of a revision of the Pacific-widespread Cyclophyllum barbatum,
we agree with Smith (1988) and retain only the specific rank. A fairly
common shrub from the understorey of the plateau forest. White fragrant
flowers fading to creamy; berries pink. Florence 10865; Florence, Chepow-Lusty
€8 Waldren 10829, 10881.
zy
Guettarda speciosa L.
(In4
A widespread species in the Tropics; varies fi-om tree to dwarf subshrub,
with white highly fragrant flowers opening in the early morning. Occurs over
most of the island and in several communities, but usually as isolated
individuals. Florence, Chepstow-Lusty @ Waldren 10823, 1O91 O.
Ixora fiagrans (Hooker & Amott) A. Gray
(End)
A small shrub from the understorey of the Pisonia forest on the plateau.
White fragrant flowers, red berries. In absence of a revision of this difficult
genus, we follow Fosberg et al. (1989) and retain this species as distinct from
relatives in French Polynesia. Endemic to Henderson. Florence, Cheptow-Lusty
€6' Waldren 70826, 10830, 10891, 11001.
zyx
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zyxwvut
FLORA OF THE PITCAIRN GROW
91
zyxwvu
Morinda myrtifolia A. Gray
(In4
- Morinda umbellata var. forsteri (Seemann) Fosberg. St John & Philipson
(1962: 193); Fosberg et al. (1989: 10).
A woody climber with small white fragrant flowers, the fruiting syncarps
blackish, eaten by birds. Forms dense tangles in the Pisonia forest on the
plateau. Florence €5' Waldren 10930; Florence, Chepstow-Lusty €5' Waldren 10903.
Psydrax odorata (G. Forster) A. C. Smith & S. Darwin
(Id
- Caizthium odoratum (G. Forster) Seemann. St John & Philipson (1962:
193); Fosberg et al. (1989: 10).
A small shrub, with white fragrant flowers and black fruits. Fairly common
on the plateau in open communities or in the understorey of Pisonia forest.
Florence 10956, 10976; Florence €5' Waldren 10855; Florence, Cliepstow-Lusty €5'
Waldren 10990.
Timonius polygamus (G. Forster) C. B. Robinson
(14
A dioecious scandent to prostrate shrub with hard wood, white evening or
night scented flowers and black fruits. Female plants have cymes reduced to
a single flower, males with 3-14 flowers per cyme. In dense stands on
limestone in the centre of the plateau, and on cliff slopes. Florence 10861,
10863; Florence, Chepstow-Lusty €5' Waldren 1083I, 10985.
v
Santalaceae
Santalum insulare var. hendersonense (Skottsberg) Fosberg & Sachet
(End)
.
.
- Santalum hendersonense Skottsberg. St John & Philipson (1962: 180).
A tree or shrub. Variable in the position of the inflorescence, which is
mostly terminal in the plateau forest but axillary in dwarf cliff-top scrub;
however, intermediates occur. Local in the plateau Pisonia and Xylosma forests,
also found along the cliffs of North and East Beaches, and at the southern
end where, in the severely salt-sprayed dwarf shrub communities, the plant
is a procumbent shrub with small glaucous leaves. Florence 70822, 10839,
10970, 10894, 10908, 10927, 10922, 1098I, 10999.
zyxwvutsr
zy
Sapindaceae
5
1'
Allophylus rhomboidalis (Nadeaud) Radlkofer
(Ind)
.
Állophylus
l sp. Fosberg et al. (1989: 7)
We retain here the name in use for East Polynesia, but a thorough study of
the A. cobbe (L.) Blume complex is needed. A small tree, occasional in the
Pisonia forest on the plateau. Rarely seen fertile. Brooke in Florence 11079;
Florence, Chepstow-Lusty €5' Waldren 11000.
Sapotaceae
Nesoluma st-johnianum Lam & B. Meeuse
(End)
A small tree with hard red wood, ramiflorous with yellow-cream flowers,
92
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J. FLORENCE ETAL.
ripe fruits black. Endemic to Henderson, very common in the plateau forest.
Florence 10963; Florence, Chepstow-Lusty 6'
Waldren 10896, 10898, 10926, 10983.
Solanaceae
zyxwv
Lycium sandwicense A. Gray
(Indl
A small prostrate subshrub, with small cylindrical succulent leaves, pink
flowers and bright red fruits. Occurs at the southern end close to the cliff
edge, in the salt-spray zone. One sight record by M. Brooke from the North
East Point. Florence, Chepstow-Lusty @ Waldren 10916.
Solanum americanum P. Miller
(AdVI
A white flowered herb. New record for the island, possible a recent
introduction by birds as there is only one location known near the South
West Point. Common on Pitcairn Island, but the islanders could not have
introduced the species to the southern end of Henderson. Brooke in Rlorence
11 109.
v
Surianaceae
Suriana maritima L.
(In4
A shrub or small tree. Purplish-black bark, pubescent twigs and yellow
flowers are good characters to separate it from Pemphis acidula, which it
superficially resembles. Only in coastal communities on coral sands (cf.
Pemphis, above). Florence 70975; Florence, Chepstow-Lusty @ Waldren 10880.
Tiliaceae
zyxwv
Triumfetta procumbens G. Forster
(In4
A perennial prostrate herb; flowers yellow ageing to orange, with burr-like
fruits. Local on the North Beach in sandy coastal vegetation. Florence 10866.
Ulmaceae
Celtis pacijïca Planchon
(Indl
- Celtis paniculata var. viridis F. Brown (1935: 32, fig. 3g); St John &
Philipson (1962: 180) yz. nov. type: Quayle & Curtis 387 (BISH)
- Celtis sp. Fosberg et al. (1989: 4).
One of the largest trees in the plateau forest, along with Pisonia and Guettarda.
Monoecious, with black fruits eaten by birds. As part of a revision of
Ulmaceae for the Flore de Polynesie Française we have studied all material of
this area, and have found no reasons to consider that Henderson Island
plants are distinct from those of the islands in French Polynesia. Size and
shape of leaves, and the pubescence of inflorescence are not reliable, while
the obscure characters of the colour of the young branches and wood
,
zyxwvu
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zyxwvut
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zyxwvut
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zyxwvut
zyxwvut
FLORA OF THE PITCAIRN GROUP
93
anatomy are of little value. Florence 10820; Florence, Chepstow-Lusty 6'Waldren
10832, 10892.
Urticaceae
Procris pedunculata (G. Forster) Wedd. var. pedunculata
(Id
A succulent herb with bright red fruits. Common in shady stations and rock
crevices on the plateau. Florence, Chepstow-Lusty G3 Waldren 10834.
Verbenaceae
Premila serratifolia L.
(In4
- Premna integrifolia L. St John & Philipson (1962: 193).
A scandent shrub with a hard wood, green fragrant flowers and black fruits.
On the plateau, locally abundant in shady or open places, forming dense
thickets. Florence 10847; Florence, Chepstow-Lusty 6' Waldren 10982.
w
Viscaceae
Korthalsella platycaula (Tieghem) Engler
(Ind)
i Korthalsella vitiensis (Tieghem) Engler. St John & Philipson (1962:
180).
- Korthalsella platycaula var. vitiensis (Tieghem) Danser. Fosberg et al.
(1989: 4).
A parasite, characterized by the flattened stem with broad articúlations,
minute yellow-olive flowers and fruits. Rare, mainly on Pisonia in the plateau
forest. Florence 10849; Florence, Chepstow-Lusty 6'
Waldren 10872, 10888, 10.994.
Korthalsella rubescem (Tieghem) Lecomte
(Indl
A parasite; differs from the preceding by stems with small narrow sub-terete
articulations, more or less rounded at the base of plant. Occurs on many
hosts, especially Glochidion, Cyclophyllum, Ixora; rare on Pisonia. More common
than K. platycaula. Florence 10843; Florence, Chepstow-Lusty €5' Waldren 10897,
10901, 10992, 11009.
Monocotyledonae
h
Agavaceae
Cordyline j?uticosa (L.) A. Chevalier
(Pol)
- Cordyline terminalis (L.) Kunth. St John & Philipson (1962: 179).
A simple, occasionally branched treelet with verrucose bark. The form
introduced by the Polynesians has green foliage and is apparently sterile.
Rare on ridge of the plateau, possibly a marker of safe paths on the cliff
margin, as in other Polynesian islands. Florence, Chepstow-Lusty 6' Waldren
10929.
94
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zyxwvu
zyx
J. FLORENCE ETAL.
Cyperaceae
Fimbristylis cymosa subsp. umbellato-capitata (Hillebrand) T. Koyama
(. I d.
- Fimbristylis sp. St John & Philipson (1962: 179).
A tufted perennial sedge. Locally common at South West End close to the
cliff, forming a closed sward. Also found at the North East Point, in a
similar habitat. Brooke in Florence 7 1003; Florence, Chepstow-Lusty €5' Waldren
10915.
I
Liliaceae
zyxwvu
I
zyxwvu
Dianella inte media Endlicher
(Indl
- Dianella intermedia var. gambierensis, F. Brown. St John &* Philipson
(1962: 179).
A perennial stoloniferous herb, the leaves finely serrate, flowers bluish-white
and fruits metallic blue. Rare in the herb layer of the Pisonia forest, and in
open Timonius scrub. Florence, Chepstow-Lusty ¿.Y Waldren 10902.
Y
Pandanaceae
Pandanus tectorius S. Parkinson ex Z
(Ind, Pol?)
- Pandanus sp. St John & Philipson (1962: 179).
Two forms (possibly involving Polynesian cultivars) occur on the island: the
first with few massive ramifications, bark light yellow to brown reddish, the
more branched with thinner branches, bark light yellowish
on North Beach, more or less invading the coconut
of cut Thespesia. As with other taxa known to be used
not clear whether Pandanus is indigenous, introduced or
both. Naturally dispersed by flotation. Very common
often forming small groves. Seems to flower
synchronously over much of the island. Florence 10874, 10875, 10260, 10961.
Poaceae
Lepturus repens (G. Forster) R. Brown
(Id
A usually stoloniferous grass, common in sandy coastal communities. A dwarf
tufted form c. 10 cm high is found on the cliff at the East Beach and on
the top of the cliff at the South West Point, in salt-sprayed areas. Florence
10858, 10969; Florence, Chepstow-Lusty ¿.Y Waldren 10907.
Thuarea involuta (G. Forster) R. Brown ex J. Roemer & J. A. Schultes
(Ind or Pol)
A stoloniferqus grass, with many long creeping shoots, spathe-like inflorescence.
Possibly a P lynesian introduction, locally abundant on the North Beach and
in the unde storey of the central Xylosma forest. The status is uncertain; in
the Tuamo{Islands
it is a common weed of Polynesian coconut plantations,
but its OCCU rence in Xylosma forest suggests it may be native on Henderson.
Florence 109 4; Florence, Chepstow-Lusty €5' Waldren 10886.
,
zyxw
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zyxw
zy
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FLORA OF THE PITCAIRN GROUP
95
Pteridopliyta
Aspleniaceae
'
Asplenium nidus L.
(Ind)
A tufted epiphytic or epilithic fern. On limestone outcrops and crevices in
Pisonia forest on the plateau, occasional at the base of the cliff in mixed
communities. Florence 10842, 10971.
Asplenium obtusatum G. Forster
A tufted epilithic fern. Local in limestone crevices close to the cliff margin
at the southern end. Florence, Chepstow-Lusty @ Waldren 1O9 17.
Y
Asplenium polyodon G. Forster
(14
- Aqjlenium lobulatum sensu St John, St John & Philipson (1962: 178),
non Mettenius
An epilithic tufted fern. One station on limestone in the south-west 1-2 k m
from the coast, rare; the second in the western pinnacles about 1 km southeast of the North West Beach, where the plant is common in the small
cavities of the dissected limestone. We regard A. polyodon in a wide sense;
the Henderson plant is very similar to the plant of Tikehau, in the Tuamotus.
In the Society Islands, the stipe and rachis are generally more scaly. Florence,
Chepstow-Lusty @ Waldren 10904, 11007.
Davalliaceae
Davallia solida (G. Forster) Swartz
(Indl
An epiphytic or terrestrial scandent fern, fronds slightly dimorphic. Fairly
common in the north-central Pisonia forests. Florence 10845.
II
Nephrolepis biserrata (Swartz) H. Schott
(In4
- Nephrolepis hirsutula seizsu Fosberg et al. (1989: 2) non (G. Forster) K.
Presl
A tufted epilithic fern, scales on stipe and rachis very sparse or absent,
pinnae entire and wide spaced, with sori in sub-marginal position. Apparently
rarer than N.hirsutula; at the base of cliff at East and North Beaches. Brooke
in Florence 11081, Florence 10962.
zyxwvu
zyxwv
Nephrolepis hirsutula (G. Forster) K.Presl
(14
- N. exaltata sensu St John, St John & Philipson (1962: 179), non (L.)
Schott?
Same habit as N. biserrata from which it differs by the scaly stipe, rachis
and pinnae; these with woolly scales, margin entire to slightly crenulate,
more closely spaced, with an acroscopic basal lobe more or less developed.
Common in the north west area in open scrub with Timonius and Scaevola,
and on cliff slopes. As we have not seen the material cited by St John, the
96
zyxwvutsrqpo
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J. FLORENCE ETAL.
synonymy is tentative. Brooke in Florence 7 7080, Florence, Chepstow-Lusty &?
Waldren 10885, 7 0925.
Polypodiaceae
zy
Phymatosorus scolopendria (N. Burman) Pichi Sermolli
(14
- Phymatodes scolopendria (Burman) Ching. St John & Philipson (1962: 179).
- Polypodium scolopendria Burman. Fosberg et al. (1989: 2).
Terrestrial and epiphytic fern with large fronds reaching 1-2 m, sori slightly
immersed in the frond. Very variable in size, depending on exposure.
Regarded by some authors as being Phymatosorus grossus, but in the absence
of a detailed study of type and other material, we retain the specific epithet
used previously for the Henderson material (Fosberg et al., 1989; St John &
Philipson, 1962). Florence 70844, 70972.
Pyrrosia seqens (G. Forster) Ching
(14
- Cyclophorus blepharolepis sensu St John. St John & Philipson (1962:
179) non Christensen.
An epiphytrc fern with long, intertwined rhizomes and small erect fronds,
grey beneath. Locally common in the Pisonia forest, rare in the Xylosma
forest, and not found close to the plateau margin. Florence 70846.
?
Psilotaceae
Psilotum nudum (L.) Beauv.
(Indl
A terrestrial erect fern with shortly creeping rhizome and pseudo-dichotomous
naked fronds. First record of this widespread species, probably overlooked.
Of erratic distribution in the open Pisoniu/Xylosma forest of the plateau.
Florence, Cht.pstoow-Lusty &Waldren
if'
70899, 70979.
Previously recorded but not founded during this survey are the following:
Sesbania coccinea subsp. atollensis (St John) Sachet, the subspecies is endemic
to East Polynesia, possibly extinct on Henderson; Jmminum didymum G.
Forster, an obscure record by Cuming; Fitchia nutans Hook. f. is definitely
an endemic of Tahiti, and the material of Cuming is mislabelled from
Henderson, like many specimens from this time; Microsorum vitiense (Baker)
Copeland is a synonym of Phymatosorus commutatus (Blume) Pichi Sermolli,
which we consider to have originated from Pitcairn and not Henderson (see
Waldren et al., 1955). Bernardi (1964) records Cuming specimens of
Weinmannia rapensis F. Brown from both Henderson and Pitcairn. These have
been overlooked in previous reports, but in view of the doubt surrounding
some of the Cuming specimens (see Fosberg et al., 1983:33), we regard these
records as uncertain.
Two other species were seen but not collected: Cocos nucfera L. and
PassiJlora malformis L., the latter in one spot at the east part of North Beach,
is a recent introduction by Pitcairners. The adventive Setaria verticillacta (L.)
Beauv. was found at the North Beach near the landing as previously reported
.
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FLORA OF THE PITCAIRN GROUP
97
by Fosberg et al. (1989); all plants noted during the expedition were destroyed.
In addition, Merelda Warren of Pitcairn Island reported an epiphytic orchid
from above the Two Tier Cave, North Beach, but searches of the site failed
to confirm this.
zyxwv
zyxw
OENO ISLAND
Dicotyledonae
Amaranthaceae
Achyranthes aspera var. velutina (Hooker & Arnott) C. Townsend
(Indl
- Archyranthes velutina forma rosea Suessenguth. St John & Philipson
(1960: 402); Fosberg et al. (1989: 16).
A small subshrub, with a grey-green velutinous pubescence covering the
whole plant; the erect inflorescence is tinged with red, flowers pink. Local
in areas of shrubby Argusia, and in the PisonialArgusia forest. Florence, ChqstowLusty €9 Waldren 10932.
Boraginaceae
Argusia argentea (L. f.) H. Heine
(In4
- Tournefortia argentea L. f. Fosberg et al. (1989: 17).
- Messerschmidia argentea (L. f.) I. Johnston. St John & Philipson (1960:
403).
Common throughout, and very variable in stature (see Waldren et a l , 1995).
Florence, Chepstow-Lusty LYWaldren 10942.
zyxwvutsr
zyxwvu
Brassicaceae
Lepidium bidentatum Montin
(Indl
Common amongst open, bushy Argusia. Florence, Chepstow-Lusty €9 Waldren
1093 I, 70949.
Clusiaceae
t
Calophyllum inophyllum L.
(Cul)
A small tree, light yellow sap, coriaceous leaves, flowers white. Introduced,
one tree planted near the Pitcairners' camp. Florence 10953.
~I
Goodeniaceae
Scaevola sericea Vahl
(Indl
- Scaevola sericea var. tuamotuensis (St John) Fosberg. Fosberg et al.
(1989: 17).
Local in shrubby Argusia and Suriana communities. Florence, Chepstow-Lusty &'
Waldren 10940.
98
zyxwvutsrqp
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Lawaceae
zyxwvu
J. FLORENCE ETAL.
Cassytha Jiliformis L.
(. I d.
Common in open Argusia areas. Florence, Chepstow-Lusty €5' Waldren 70933.
Moraceae
Ficus elastica Roxburgh ex Hornemann
(Cul)
A small tree with many aerial roots, abundant milky sap, and large leathery
leaves; stipules red. Introduced, one tree planted near the Pitcairners' camp.
Florence 70952.
Nyctaginaceae
Boerhavia tetrandra G. Forster
(Indl
- Boerhavia dzfisa var. tetrandra (G. Forster) Heimerl. St John &
Philipson (1960: 402).
Common in Argusia scrub. Florence, Chepstow-Lusty €5' Waldren 70946.
Pisonia grandis R. Brown
(In4
Local, forming a forest with tall Argusia at the southern end, in phosphorusenriched soil (S. Waldren & L. Scally, unpublished data). Florence 70955,
Florence, Chepstow-Lusty €5' Waldren 70938.
zyxwvu
Rubiaceae
Y
zyxwvu
Hedyotis romanzofiensis (Chamisso & Schlechtendal) Fosberg
(Id
A subshrub, flowers green, fruits white but tinged with violet at maturity.
Locally common in fairly bare sandy areas near the shore, less common on
coral rubble. Occurs from Eastern Polynesian to Kiribati, the Phoenix and
Line Islands. Florence, Chepstow-Lusty €5' Waldren 70935, 70947, 70957.
Solanaceae
Solanum viride G. Forster ex K. P. Sprengel non R. Brown
(Nat)
- Solanum tuamotuense St John. St John & Philipson (1960: 403).
A perennial herb, more or less branched. One station at south east end, at
edge of PisonialArgusia forest. Possibly indigenous, but more probably a
Polynesian introduction. R. E. Symon (personal communication) has indicated
this previously unpublished synonymy to us. Florence, Chepstow-Lusty €5' Waldren
7 093 7.
Surianaceae
Suriana maritima L.
(14
Common on sandy beach fronts, and scattered about the sand spit. Florence,
Chepstow-Lusty d5' Waldren 70943.
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FLORA OF THE PITCAIRN GROUP
99
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zyxwvut
Tiliaceae
Triumfetta procumbens G. Forster
(Indl
Very rare, a few individuals on the sand spit. First record for Oeno; possibly
a recent colonist, despite its abundance on Pacific atolls and on Henderson
(Waldren et al., in press). Florence, Chepstow-Lusty & Waldren 10944.
Monocotyledonae
Pandanaceae
Pandanus tectorius S. Parkinson ex Z
(14
- Pandanus feruliferus St John. St John & Philipson (1960: 402).
Common on gravel and sand. This form is close to that of the slenderbranched Henderson form. Florence, Chepstow-Lusty & Waldren 10934, 10948.
L
Poaceae
Lepturus repens (G. Forster) R. Brown
(In4
Common in open areas amongst Argusia. Florence, Chepstow-Lusty €9 Waldren
10936.
Setaria verticillata (L.) Beauv.
(Ad4
A new record, probably introduced from Pitcairn (where it is common) by
the islanders who visit Oeno for holidays. Florence, Chepstow-Lusty €9 Waldren
10950.
Gymnospermae
Araucariaceae
*
Araucaria heterophylla (R. Salisbury) Franco
(Cul)
The Norfolk Island pine, planted near the Pitcairners’ camp. Two trees seen.
Florence 10954.
Pteridophyta
Aspleniaceae
Asplenium nidus L.
(In4
Restricted to the PisonialArgusia forest, but common there. Florence, ChepstowLusty & Waldren 10939.
100
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J. FLORENCE ETAL.
Polypodia ceae
Phymatosorus scolopendria (Burman) Pichi Sermoli
(In4
- Phymatodes scolopendria (Burman) Ching. St John & Philipson (1960:
402).
- Polypodium scolopendria Burman. Fosberg et al. (1989: 16).
As on Henderson, highly variable in size and lobation, varying from almost
simple fronds in exposed coastal habitat to large fronds over 2 m long on
richer soils in the PisonialArgusia forest. Florence, Chepstow-Lusty ¿
Waldren
i?
10945, I094 7.
The following previously recorded species were not found during the
present survey: Brassica jzincea (L.) Cosson & Czernaev, a fugacious weed
collected once by Williams in 1956; Crinum aff. asiaticum, an ornamental no
longer present; and the endemic Bidens hendersonensis var. oenoensis Sherff,
which was not found despite a careful search.
I
PITCAIRN ISLAND
Dicotyledonae
Aizoaceae
Sesuvium portulacastrum (L.) L.
(In4
Rare on basalt coastal cliffs at Bounty Bay. Florence 10772.
Amaranthaceae
Achyranthes aspera L. var. aspera
(Pol)
An introduced Polynesian weed. Leaves grazed by goats. One station seen
at Down Rope. Florence 11020.
Alternanthera brasiliana (L.) Kuntze
(Nat)
Introduced ornamental, a reddish-purple plant with white capitula. Naturalized
on roadsides. Florence €3 Waldren 11034.
zyxw
Amaranthus viridis L.
(Ad4
A coarse herb, utricule indehiscent, 3 tepals. A common weed in gardens
and along roadside. Florence 70750, 10810.
Apiaceae
Apium leptophyllum (Persoon) F. H. Mueller ex Bentham
(Add
A rare weed, leaves dissected with filiform divisions, fruit circular. FZorence
1 1023.
zyxwvu
zyxwv
zyx
zyxwvut
FLORA OF THE PITCAIRN GROUP
101
Apium prostratum Labillardiere
(Indl
- Apium australe Thouars. St John (1978: 45).
A biennial herb, leaves with large divisions, corky circular fruits. Probably
indigenous on sea cliffs of the east and south coast; rare. Florence 10777,
11017.
Apocynaceae
Cerbera manghas L.
(In4
A small tree with abundant milky sap, fallen corolla was white. A tentative
determination, in the absence of mature flowers. Rare at Tedside, on a slope
in Homalium forest. Florence 1 1028.
Araliaceae
zyxwv
zy
zyx
(Cul)
An undetermined small treelet, naturalised along roadside. Said to be
introduced from Panama. Florence C? Waldren 1 1037.
Asteraceae
Bidens mathewsii Sherff
(End)
An endemic subshrub less than 1 m high, with small yellow capitula. Very
rare at the Rope, in disturbed Dicranopteris community. Brooke in Florence
11110; Florence 11015.
Bidens pilosa L.
(Ad4
A pantropical weed, capitula generally without white ligulate flowers. Common
in gardens, fields and roadsides. Florence 10746; Florence 6' Waldren 1 1041.
Conyza bonariensis (L.) Cronquist
(Ad4
A suffruticose herb, .capitula creamy white. Introduced and widespread in
various disturbed communities. Florence 10761.
Sigesbeckia orientalis L.
(AdVI
A suffruticose herb, capitula glandulous, yellow. Rare on the disturbed
summital crest. Florence 6' Waldren 11042.
Sonchus oleraceus L.
(AdVI
A lactiferous herb, capitula lemon-yellow. A common weed in gardens and
along roadsides. Florence 10765.
Synedrella nodijlora (L.) J. Gaertner
(Ad4
An introduced herb, capitula with lemon-yellow ligules. Found on a sunny
roadside. Florence 1O 747.
102
zyxwvutsrqpo
zyxwvu
zyxwvu
J. FLORENCE ETAL.
Taraxacum oficinale G. Weber
(Add
A tuberized herb, capitula bright yellow. In the lawn around the Radio
Station. Florence 11024.
firnonia cinerea var. parvgora (Reinwardt ex Blume) A.P. DC.
(Adv)
A small herb with violet capitula. Found in weedy and coastal habitats.
Florence 10794.
Begoniaceae
Begonia sp.
(Cul)
A cultivated hybrid, caulescent, with pink flowers. Ornamental in the village,
sub-spontaneous. Florence 10814.
Boraginaceae
Argusia argentea (L. f.) H. Heine
(Id
O n basaltic coast. One tree at Bounty Bay, apparently rare. Florence 10799.
Brassicaceae
Coronopus didymus (L.) Smith
(Ad4
A small prostrate herb with white flowers, silicules circular. Introduced, new
record for t he island; one station on bare basaltic coastal rock north of
Bounty Bay. Florence 10798.
Caprifoliaceae
Lonicera japonica Thunberg
(Cul)
An ornamental liana, fragrant creamy flowers. Cultivated, tending to escape
but not fully naturalized. Florence 10760.
Convolvulaceae
zyxwv
zyxwv
Jjjomoea indica (L.) Merrill
(Nat)
A climbing vine, milky juice rare, large showy blue flowers, throat purplish.
An introduced ornamental, naturalized around Adamstown, and becoming a
troublesome weed. Florence 10784.
Ipomoea macrantha J. Roemer & J. A. Schultes
(. 1 4.
Rare, one coastal station at Bounty Bay. Florence 10785.
zyxw
zyxwvuts
FLORA OF THE PITCAIRN GROUP
Cucuribtaceae
103
Cucumis sativus L.
(Nat)
A climbing vine, fruit shorter and larger than the cultivated plant. Naturalized
on a coastal cliff beneath the village rubbish dump area. Florence 10796.
Euphorbiaceae
zyxwvut
Chamaesyce hirta (L.) Millspaugh
(Ad4
A weed, leaves with a reddish central spot above. Common along roadsides
and in gardens. Florence 10812.
Chamaesyce sparrmannii (Boissier) Hurusawa
(In4
- Euphorbia pitcairnemis F. Brown (1935: 134, Fig 21d).
- Euphorbia ramosissima Hooker & Amott. St John (1987: 39).
Apparently very rare, one plant at Bounty Bay, in sheltered crevices of
basaltic coastal rocks. Has the same prostrate habit as the plants have on
Henderson in exposed coastal habitats. Florence 10797.
Eupliorbia peplus L.
(Adv)
A weed, inflorescences with cornute yellowish glands. Rare on roadsides.
Florence €5' Waldren 11048.
Euphorbia pulcherrima Willdenow ex Klotzsch
(Cul)
A shrub with abundant milky sap and showy red bracts, involucral glands
yellow. Common ornamental plant. Florence 10809.
Glochidion pitcairnense (F. Brown) St John
(In4
A small tree, glabrous in all parts, leaves slightly bullate, fruits more deeply
lobed than the following species. Rare in open fern community. Florence
10736, Florence & Waldren 11047.
Glochidion sp.
(End)
A striking new species, belonging to the group of East Polynesian species
characterized by a pubescent ovary with 4-5 locules, which is centred around
G. taitensis Baillon ex J. Mueller. The Pitcairn plant differs by its more
massive ovary and shorter stylar column. The taxon will be described in a
separate paper. Endemic to Pitcairn Island, at edge of disturbed forest or in
open mixed grass-fern community, apparently not common. Florence 10728,
10754; Florence & Chepstow-Lusty 10730.
Flacourtiaceae
Homalium taypau St John
(End)
A medium low-branched tree, flowers purple. An endeniic species, related
104
zyxwvutsrqpo
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z
J. FLORENCE ETAL.
to H. acuminatum of Rarotonga. Common in the forested valleys, but these
âre being invaded by Syzygium jambos (see Wddren et al., in press). FZorence
€9 Waldren 11043.
zyx
Xylosma suaveolens (J. R. & G. Forster) G. Forster
(Indl
- Xylosma suaveolens subsp. haroldii Sleumer. St John (1987: 42).
A small depressed shrub, young green fruits. One specimen seen on the
summital crest. Apparently different from the plant on Henderson, but more
material is needed for a precise determination. Florence ti? Waldren 77040,
Goodeniaceae
Scaevola sericea Vahl
(Indl
- Scaevola taccada var. tuamotuensis St John. St John (1987: 53).
One plant seen on basaltic soil from the beach of Bounty Bay. Florence
10791.
Hernandiaceae
Hernandia sonora L.
(W
Hernandia nymphaeifolia (Presl.) Kubitzki, St John (1987: 34).
A medium-sized tree, peltate leaves, immature fruits translucent yellow turning
to red. Apparently rare in disturbed valley forests. Florence €9 Chepstow-Lusty
10729.
-
Lamiaceae
Ballota nipa L.
(Ad4
A lightly aromatic herbaceous weed, flowers with a 10-nerved calyx, corolla
2-lipped, pink, four stamens. A rare weed along a roadside. New record for
Pitcairn. Florence 7 7022.
Lauraceae
Persea americana P. Miller
(Nat)
Avocado is locally naturalized in secondary forests. Florence 7 7074.
Leguminosae
Abrus precatorius L. subsp. precatorius
(Nat)
.
,
A woody climber, seeds black with a vermilion aril. Roadside scrub. Florence
€9 Waldren 11038.
Albizia saman (N. Jacquin) F. H. Mueller
(Cul)
zyxwvu
zyxwvuts
FLORA OF THE PITCAIRN GROUP
105
A large ornamental tree, flowers with showy white and pink stamens. Planted
in a garden. Florence 10801.
Bauhinia monandra Kurz
(Nat)
A tree, large pink flowers, one fertile stamen. Cultivated for handcrafts, and
more or less naturalized around the village. Florence 10804.
Centrosema pubescens Bentham
(Add
An introduced scrambling vine with large pink flowers. A new record, seen
in one spot at Adamstown. Florence 10803.
zyxwvu
zyxwvu
zyxwv
Desmodium tortuosum (Swartz) A.P. DC
(Add
A suffruticose herb, small mauve flowers, legumes deeply incised on both
sides. A new record, along the roadside at Adamstown. Florence 10783.
Elythrina variegatu L.
(Poll
- Elythrina variegata var. orientalis (L.) Merrill. St John (1987: 36);
Fosberg et al. (1989: 13).
A tree, almost leafless at flowering, inflorescences with orange-red flowers.
Introduced by Polynesians; rare, in a ravine of McCoy’s Valley. Florence
11021.
\
I
zyxwvutsrqponml
Lablab purpureus (L.) Sweet
- Dolichos lablab L. Fosberg et al. (1989: 13).
(Nat)
A low scrambling vine, white flowers fading to cream. Escaped from
cultivation, common. Florence 11032.
Malvaceae
Hibiscus tiliaceus L.
(14
A small tree with more or less arching branches, flowers yellow with purple
petal bases. Common in all forested valleys on steep slopes, rarer in coastal
habitats. Florence 10787.
L
Malvastrum coromandelianum (L.) Garcke
(Ad4
A weedy herb, more or less prostrate, with pale yellow flowers. Common
on roadsides. Florence 10744.
Sida rhombfolia L. subsp. rhombfolia
(Ad4
A weedy herb, flowers light yellow. Common in old fields and along
roadsides. Florence 10745.
Thespesia populnea (L.) Solander ex Correa
(Pol?)
A small tree, yellow flowers with red-purple petal bases. Occurs on the crest
106
zyxwvutsrqpon
zyxwvu
J. FLORENCE ETAL.
above the Radio Station, and around Adamstown; probably a Polynesian
introduction. Florence 70737.
Myrtaceae
Eugenia reinwardtiana (Blume) A.P. DC.
(14
Rare on coastal cliffs at Bounty Bay. Florence 70780, 70790.
zyxwvu
Eugenia uniflora L.
(Nat)
An introduced shrub, white flowers. Used as a hedge in gardens, becoming
naturalized. Florence €i? Waldren 7 7049.
Metrosideros collina (J. R. & G. Forster) A. Gray s.1.
(In&
A small kee or shrub, vermilion flowers. Occasional on dry crests and slopes
in open communities. We retain only the specific rank here; a full revision
of this species is needed. Florence 70768; Florence €i? Waldren 77045.
Fsidium cattleianum Sabine
(Nat)
A shrub widely naturalized on the island. Florence 70757.
Syygium jambos (L.) Alston
(Nat)
- yqygium jambos err. typ. Fosberg et al. (1989: 14).
A small tree with pale yellow flowers. The major conservation problem of
Pitcairn, invading a variety of communities in various ecological situations
and threatening the survival of many native plants (Waldren et al., in press).
Florence 7 7033.
Nyctaginaceae
Mirabilis jalapa L.
(Nat)
An ornamental herb, flowers white or yellow. In gardens, but more or less
naturalized. Florence 70800.
Oleaceae
Jasminum grandiflorum L.
(Cul)
An ornamental liana, white flowers strongly fragrant. Cultivated in gardens.
Florence 70807.
Oxalidaceae
Oxalis corniculata L.
(Add
A prostrate herb, yellow flowers. Common on roadsides. Florence 70877.
zyxwv
zyxwvuts
zyxwvu
zyxwvuts
zyxwvu
zyx
zyxwvuts
FLORA OF THE PITCAIRN GROUP
Passifloraceae
107
Pmsijlora laurifolia L.
(Nat)
A climbing vine, bracts free. In cultivation, but more or less naturalized.
Florence €3 Waldren 11035.
Passijlora malformis L.
(Nat)
A vigorous vine, bracts united at the base. More common and aggressive
than the previous, local in dense tangles at edge of the forest. Florence 10748.
Piperaceae
Peperomia blanda var. floribunda (Miquel) H. Huber
(Ind)
- Peperomia leptostachya var. macrophylla (Setchell) Yuncker. St John
(1987: 29).
A small succulent herb, twigs and leaves pubescent. O n coastal cliffs or
shaded rocks in Homalium forests. Florence 11025; Waldren in Florence 10816.
\
I
Peperomia rapensis F. Brown
(In4
A small prostrate Peperomia characterized by opposite to sub-opposite leaves
and stems with stiff hairs less than 0.2 mm long. Very rare on coastal cliffs
at Down Rope. Distribution highly disjunct: also found 1500 k m to the west,
in the Austral Islands. Florence 11016.
Plantaginaceae
Plantago major L.
(AdVI
An introduced weed, found mainly in coastal communities. Florence 10788.
Rosaceae
Fragaria x ananassa Duchesne
(Nat)
A strawberry, no mature fruits seen. Remnant of cultivation and more or
less naturalized on roadsides. Florence 10734.
Rubiaceae
Guettarda speciosa L.
(In4
A rare tree from basaltic coast at Bounty Bay. Florence 10767.
Rutaceae
Citrus medica L.
(Cul)
A small tree slightly spiny, petiole wingless, lamina not articulate on petiole.
A tentative determination in the absence of mature fruit. Said to be introduced
108
zyxwvutsrqpo
zyxwvu
zy
J. FLORENCE ETAL.
from New Zealand (R. Warren, personal communication). Florence
11036.
¿Y
Waldren
Solanaceae
Lycium sandwicense A. Gray
(W
Coastal cliffs at Bounty Bay, rare. Florence 10778, 10795.
Lycopersicon esculentum P. Miller
(Nat)
Glandular climbing herb, yellow flowers. Naturalized in an old garden.
Florence 10808.
Nicotiana tabacum L.
(Nat)
A tall glandular herb, pink flowers. Introduced, naturalized sparsely on
roadsides. Florence 11013.
Solanum americanum P. Miller
(Ad4
A prostrate herb, flowers white, black fruits. A weed, found also in coastal
vegetation. Florence 10774.
Verbenaceae
Lantana camara L.
(Nat)
A climbing shrub, less prickly than in French Polynesia, flowers orange to
red. Mainly in old plantations and disturbed areas, and in some places a
threat to native vegetation. Florence 10749.
zyxwvu
Verbena litoralis Kunth
(Ad4
A small much-branched herb, pink flowers. Rare in an open rocky station
at Tedside. Florence 11031.
Monocotyledonae
Agavaceae
Cordyline fiuticosa (L.) A. Chevalier
(Pol)
Occasionally flowering (cf. Henderson, above). Locally common in fern and
grass communities, and roadsides. Florence ¿Y Waldren 11039.
Cannaceae
Canna indica L.
(Nat)
A rhizomatous herb, red flowers. Introduced, largely naturalized on roadsides
and in secondary forest. Florence 10815.
zyxw
zyxwvuts
zyxwvut
zyx
FLORA OF THE PITCAIRN GROUP
Commelinaceae
109
Commelina dafisa Burman
(Ad4
A creeping perennial, blue ephemeral flowers. Roadside at Adamstown.
Florence 10802.
'
Cyperaceae
Icy llinga brevifolia Rottb oell
(Ad4
- Cyperus brevifolius (Rottb.) Hassk. St John (1987: 24).
A stoloniferous sedge, heads green. Occasional in grassy communities. Florence
10769.
Kyllinga nemoralis (J. R. & G. Forster) Dandy ex Hutchinson & Dalziel
(Add
Like the previous, but heads white. Common at Adamstown, in weedy
places. Florence 10806.
,
Mariscus javanicus (Houttuyn) Merrill & Metcalfe
(Ad4
Cyperus javanicus Houttuyn. St John (1987: 25).
A tufted perennial sedge, with sharp glaucous leaves. Local in coastal
vegetation, scattered on the summital crest. Florence 10793.
Orchidaceae
Taeniophyllum fasciola (G. Forster) H. G. Reichenbach
(W
Taeniophyllum sp. St John (1987: 29).
A leafless epiphyte, narrow photosynthetic roots, erect capsules. Rare in
Homalium forest. Florence 1102 7.
-
Poaceae
Cynodon dactylon (L.) Persoon
(Ad4
A stoloniferous grass. Common in lawns and on roadsides. Florence 10762.
Digitaria setigera Roth ex J. Roemer & J. A. Schultes
(Ad4
A grass with white hairs on the culms, panicles with 6-10 spikes, which
remain bunched. Common in coastal communities, along roadsides and fields.
Florence 10763, 10789, 10813.
Eleusine indica (L.) J. Gaertner
(Ad4
A perennial tufted grass. Weedy open places along roads. Florence 10786.
Lepturus repens (G. Forster) R. Brown
(In4
Rare in coastal vegetation at Bounty Bay. Florence 10779.
110
zyxwvu
zyxwv
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zy
J. FLORENCE ETAL.
Oplismenus hirtellus (L.) Palisot
(A&)
A stoloniferous prostrate grass. Rare in shady understorey of secondary
Homalium forest. Florence 6'Chepstow-Lusty 70737.
Paspalum conjugatum B. Bergius
(Add
Stoloniferous grass, panicle of two digitate spikes forming a T-shape. Common
in open secondary scrub. Florence 70782.
Paspalum orbidare G. Forster
(AdVI
Tufted tall grass, panicle of 3-7 alternate spikes. Rare in open secondary
communities. Florence 70777.
Setaria verticillata (L.) Beauv.
(Ad4
- Setaria pumila (Poir.) Roemer & Schultes. St John (1987: 24).
On roadsides, common. Florence 70764.
Sorghum sudanense (Piper) Stapf
(Adv)
- Sorghum halepense sensu Fosberg et al. non (L.) Persoon, Fosberg et al.
(1989: 12)
A tall grass. Roadsides, disturbed areas, very aggressive and invading the
Dicranopteris community at moderate altitude. Florence 70787.
Sporobolus indicus (L.) R. Brown
(Adv)
A tufted grass, panicles green tinged with violet. In grass communities at
low altitude. Florence 70770.
Gymnospermae
Pinaceae
Pinus caribaea var. hondurensis Barett & Golfari
(Cul)
A young tree planted on the roadside in the hills above Adamstown.
Introduced from the Gambier Islands. Florence 70759.
Pteridophyta
Aspleniaceae
Arachniodes aristata (G. Forster) Tindale
(Indl
- Rumohra aristata (G. Forster) Ching. St John (1987: 19).
Terrestrial, with a creeping rhizome, shiny dark green frond, aristate pinnules.
Rare in the Homalium forest at high altitude. Florence 70739.
Asplenium obtusatum G. Forster
(In4
Locally common on coastal cliffs. Florence 70775, 77079.
*
zyxw
zyxw
zyxwvu
FLORA OF THE PITCAIRN GROUP
111
Asplenium shuttleworthianum Kunze
(14
- Loxoscaphe gibberosum T. Moore. St John (1987: 20).
Terrestrial or epilithic, rhizome short creeping, black palea, dark green frond.
Anomalous distribution: New Zealand, Fiji and Pitcairn. Locally common on
coastal cliffs, rarer in the understorey of Homalium forest. We have previously
discussed the taxonomic problems in Loxoscaphe and A. shuttleworthianum, our
collections agree with the description of A. shuttleworthianum. Future collectors
should pay detailed attention to these taxa. Florence 10747, 10756, 10776,
zyxw
zyx
11018.
Aspidiaceae
Ctenitis cumingii Holttum
(End)
Terrestrial, rhizome short creeping. This endemic differs from C. sciaphila of
French Polynesia by the lack of rufous palea on the stipes. Very rare, seen
in one place with Angiopteris. Not mentioned by St John (1987). Florence
*
10758.
Blechnaceae
Doodia inedia R. Brown s.1.
(14
A tufted erect fern; frond dark, brittle. Rare in shady humid places in the
Homalium forests. Florence 10738.
Cyatheaceae
Cyathea medullaris (G. Forster) Swartz
(Indl
- Cyathea cumingii Baker. St John (1987: 17).
The only tree-fern, with stems up to 7 m high and 15 cm diameter. Rare
below the summital crest in a disturbed MetrosideroslHomalium forest, very
rare elsewhere. Florence & Waldren 11044.
Davalliaceae
Davallia solida (G. Forster) Swartz
(Indl
Rare in the Dicranopteris community. Florence 10735.
.
zyxwv
Nephrolepis cordifolia (L.) K. Presl
(Ind or Adv?)
An erect stoloniferous fern, scales obscure on the stipe and rachis, pinnae
distinctly crenate, indusium reniform. Rare in mixed grass-fern community
at Tedside. New for the island, status obscure. Florence 71030.
Nephrolepis hirsutula (G. Forster) K. Presl
(In4
A larger and more common fern than N. cordifoolia, in mixed grass-fern
communities. Florence 70733, 10753, 71029.
112
zyxwvutsrq
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J. FLORENCE ETAL.
Gleicheniaceae
Dicranopteris liwuris (Burman) Underwood
(Id
Terrestrial in dense tangled growths. Common above 30 m elevation in open
areas. Florence 10752.
Hymenophyllaceae
Trichomanes endlicherianum K. Pres1
(In4
The only filmy fern of Pitcairn. In a humid valley on shaded basaltic rock.
Same station as Angiopteris and Ctenitis in Homalium-Syqgium forest. Florence
10755.
zyxw
zyxwvu
zyxwvu
Marattiaceae
Angiopteris chauliodonta E. B. Copeland
(End)
A large erect fern, with a globular rhizome up to 30 cm; the stipe naked
and glaucous, with the frond reaching 3 m. In the absence of a recent
revision of the genus we retain Copeland’s name for the Pitcairn plant. A
very rare endemic, threatened by Syygium invading the native forests (Waldren
et al., in press). Florence 10757.
d
Polypodiaceae
Phymatosorus commutatus (Blume) Pichi Sermolli
(Id
- Phymatodes sylvaticum (Brack.) Copeland. St John (1987: 21).
A creeping fern, frond with very small or punctiform sori, slightly pustulate,
not fragrant like the ornamental form. Very rare by a shady stream bank.
Florence 70743.
8
Phymatosorus powellii (T. G. Baker) Pichi Sermolli
(14
- Microsorium pitcairnense E. Copeland (1938: 74)
- Polypodium pitcairnense (Copeland) Brownlie, St John (1987: 21).
- ‘Microsorium’ type: Pitcairn: Fosberg & Clark 11311 (BISH) syn. nov.
Superficially similar to P. scolopendria, differing by the more narrow pinnae,
undulate margins and sori forming pustules on the upper surface of the
pinnae. Very similar to the material of the Society and Cook Islands. Rare
at high altitude in Homalium forest. Florence @ Waldren 71046.
Phymatosorus scolopendria (Burman) Pichi Sermolli
(Indl
Phymatodes scolopendria (Burman) Ching. St John (1987: 21).
Common in a variety of habitats, varying in dissection and size of the
lamina. See comments for Henderson Island. Florence 70792.
.
zyxwv
zyx
zyxwvut
FLORA OF THE PITCAIRN GROUP
113
Qrrosia serpens (G. Forster) Ching
(In4
- Qrrosia angustata sensu St John (1987).
Epiphytic and epilithic, in sunny places. Rare at Tedside. Florence 7 7026.
Psilotaceae
Psilotum nudum (L.) Beauv.
(Ind)
Psilotum nudun (L.) P. Beauv. err. typ. St John (1987: 16).
Terrestrial. One station seen, on a shady stream bank. Florence 70742.
Thelypteridaceae
v
*
Christella parasitica (L.) Léveillé
(In4
- Cyclosorus parasiticus (L.) Farw. St John (1987: 19).
- Thelypteris cf. parasitica (L.) Tard. Fosberg et al. (1989: 12).
A terrestrial creeping fern, frond with lowest pinnae deflexed, with the
acroscopic basal lobes well developed; sori black. Rare in the understorey
of forests or shady roadsides, sometimes grown in the gardens. Florence 70805.
Pneumatopteris costata var. hispida Holttum
(In4
Rhizome erect, costa and rachis pubescent beneath, indusia distinct. Rare in
shady roadsides and low-altitude forest. Found also on Rarotonga and Easter
Island. Florence 70732.
*
4
Sight records of uncollected plants: Aleurites moluccana (L.) Willd.; Araucaria
heterophylla (R. Salisbury) Franco; Catharanthus roseus (L.) G. Don; Citrullus
lanatus (Thunb.) Matsum & Nakai; Coix lacryma-jobi L. (fruits only collected);
Ficus prolixa G. Forster; Leucaena leucocephala (Lam.) De Wit; Melia azaderach
L.; Morinda citrfolia L.; Morinda myrtifolia A. Gray ( =Morinda forsteri Seem.
St John, 1987 52), the only indigenous species in this group; Ocinzuin basilicum
L.; Polyscias guilfolei (Bull) L. H. Bailey; Psidium guajaua L.; Tagetes patula L.;
Terminalia catappa L.; Zingiber zerumbet (L.) Roscoe.
Garden sight records not previously recorded: Acalypha wilkesiana Muell.
Arg.; Arbutus unedo L.; Codiaeum variegatum (L.) Bl.; Cucurbita cf. maxima
Duchesne ex Lam.; Gerbera jamesonii Bol. ex Adlam.; Hydrangea macrophylla
(Thunb.) Ser.; Leucanthemum vulgare Lam.; Rhododendron cf. indicum (L.) Sweet.
The following have previously been recorded as native from Pitcairn but
were not found on this survey: Abutilon pitcairnense Fosberg, an endemic of
Pitcairn with only three collections known; Alyxia scandens Roem. & Schultes,
one collection by Miss R. A. Young; Capparis cordifolia Lam., Whitney
Expedition of 1922; Celtis paciJica G. Planch.; Cocculus ferrandianus Gaud.;
Coprosma rapensis F. Brown var beneJica (Oliver) Fosberg, endemic; Cyclophyllum
barbatum (G. Forster) N. Halle & Florence; Dianella intermedia Endlicher;
Diplazium harpeodes T. Moore; Jasminum didymunz G. Forster; Lepidiuin
bidentatum Montin; Myrsine sp. aff. niauensis, apparently endemic; Osteomeles
anthyllidifolia (Sm.) Lindl.; Sapindus saponaria L.; Vittaria elongata Sw., said by
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114
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J. FLORENCE ETAL,
St John (1987) to be rare in 1934 and Weinmannia rapensis F. Brown, a
Cuming record of uncertain status.
St John (1987) also lists Barringtonia asiatica (L.) Kurz and Calophyllum
inophyllum L as native, we consider them to Polynesian introductions.
ACKNOWLEDGEMENTS
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We are grateful to the Pitcairn Island Council and the Pitcairn Island
Commissioner for permission to visit the islands and to collect specimens.
We are especially grateful to the Pitcairn Islanders for their wonderful
hospitality during our stay on Pitcairn, and especially thank Reynold & Nola,
Terry & Yula, and Brian & Kari. Our visit to the islands as part of the Sir
Peter Scott Commemorative Expedition was generously supported by the
following major sponsors: The Royal Society, International Council for
Bird Preservation, British Ornithologists’ Union, J. A. Shirley, Foreign &
Commonwealth Office UK, UNESCO; all other sponsors are acknowledged
in the expedition report of 1992. We would also like to thank Helen Fortune
Hopkins for drawing our attention to the Bernardi monograph. This is paper
33 of the Sir Peter Scott Commemorative Expedition to the Pitcairn Islands.
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REFERENCES
Balgooy MM. van 1971. Plant-geography of the Pacific. Blumea, supplement 6: 222 pp.
Brown FBH.1935. Flora of Southeastern Polynesia. III. Dicotyledons. B.P. Bishofi Museum Bulletin 730:
386 pp., 9 pl., 70 fig.
Copeland EB. 1938. Ferns of Southeastern Polynesia. Occasional Papers of the B.P. Bishop Museum 14:
45-10 1.
Florence J. 1987. Endemisme et évolution de la flore de la Polynesie Française. Bulletin de la Societe
Zoologique de France 112: 369-380.
Fosberg FR, Paulay G, Spencer T, Oliver R 1989. New collections and notes on the plants of
Henderson, Pitcairn, Oeno, and Ducie Islands. Atoll Research Bulletin 329.
Fosberg FR, Sachet M-H, Stoddart D R 1983. Henderson Island (southeastern Polynesia): a summary
of current knowledge. Atoll Research Bulletin 272.
Rehder HA, Randall JE. 1975. Ducie Atoll: its history, physiography and biota. Atoll Research Bulletin
7 83.
Smith AC. 1988. Flora Vitiensis Nova, volume 4. Honolulu, Hawaii: Pacific Tropical Botanic Garden.
St John H. 1987. An account of the flora of Pitcaim Island with new Pandanus species. Pa@ Plant
Studies 46: Honolulu, Hawaii: privately published.
St John H, Philipson WR. 1960. List of the flora of Oeno Atoll, Tuamotu archipelago, South-Central
Pacific Ocean. Transactions of the Royal Society of New Zealand 88: 401-403.
St John H, Philipson WR. 1962. An account of the flora of Henderson Island, South Pacific Ocean.
Transactions of the Royal Society of New Zealand, Botany 1: 179-194.
Waldren S, Florence J & Chepstow-Lusty AJ. In press. Rare and endemic vascular plants of the
Pitcairn Islands, south-central Pacific Ocean: a conservation appraisal.
Waldren S, Florence J, Chepstow-Lusty AJ. 1995. A comparison of the vegetation communities from
the Islands of the Pitcairn Group. Biological Journal of the Linnean Society 56: 121-144.
Zizka G. 1991. The flowering plants of Easter Island. Palmarum Hortus Francofortensis, 3: pp 108.
Palmengarten, Frankfurt, Germany.
APPENDIX 1: TAXONOMIC POLLEN NOTES OF SOME OF THE ENDEMIC SPECIES
AND VARIETIES OF HENDERSON ISLAND
Prepared by A. J. Chepstow-Lusty
Pollen was collected from the reproductive structures of living specimens in the field and preserved in
90% ethanol, 5%acetic acid and 5% formaldehyde. In the laboratory, the material underwent acetolysis,
Y
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FLORA OF THE PITCAIRN GROUP
115
before being mounted in silicone oil for examination under light microscopy. Prepared slides were
studied with a calibrated Leih microscope and photographs were taken on a Nikon labophot with a
Nikon FX-35A camera attachment. All exposures were at a magnification of 4 0 x , except for Peperomia
hendersonensis (oil immersion at 100 x) . Reference slides are located at Department of Plant Sciences,
Cambridge University, UK and Geography Department, Massey University, New Zealand.
All the species described produce pollen singly as a monad. Descriptions were firstly concemed with
basic criteria such as symmetry, either bilateral or radiosymmetric. Radiosymmetric grains were further
classified as isopolar or heterpolar or, if lacking in polarity, as apolar. Pollen grains were then classified
using the morphological type nomenclature of Faegri & Iversen (1964), in conjunction with details of
apertures.
Shape is another primary criterion. All the grain types that are radiosymmetric were described
according to Erdtman (1943) depending on the ratios of their polar and equatorial axes (P:E ratios):
perprolate >2, prolate 2-1.33, subprolate 1.33-1.14, prolate spheroidal 1.14-1.00, oblate spheroidal
1.00-0.88, suboblate 0.88-0.75, oblate 0.75-0.50, and peroblate < 0.50. Exine structure and sculpture
were penultimately dealt with based on the usage of Faegri & Iversen (1964), followed by the range
of the lengths of the polar and equatorial axes.
Alyxia sp. - asymmetrically barrel shaped, heteropolar, one side straight, the other side more convex;
diporate, giant pores about 30 pm across, surrounded by slight thickenings 3 pm wide; exine c. 1.5
pm thick, with minute reticulation or slightly irregular pitting; 47-50 x 56-60 prn. Very few grains from
specimens collected, Figure 1.
4
,
Bidens hendersonensis var. hendersonensis Sherff - radiosymmetric, isopolar; tricolporate, colpi long, pores
small, not well defined; spheroidal, amb circular; exine tectate, echinate, echini long, conical with
curved pointed tips, c. 6 pm in height and 4 pm across the base, in a meridonal arrangement, c. 9
pm distant from each other; 32-33 x 29-33 pm. Figure 2, polar view.
Glochidion pitcairnense (F. Brown) H. St John - radiosymmetric, isopolar; tetracolporate, frequently
pentacolporate, colpae thin and long reaching to the proximity of the poles, pores circular but often
indistinct c. 1.5 pm in diameter; oblate spheroidal, amb circular; exine c. 1.5 pm thick, perreticulate,
homobrochate, brochi c. 1 pm in diameter; 21-22x21-23 pm. Figure 3. A, polar and B, equatorial
views.
Xylosma suaveolens subsp. haroldii Sleumer - radiosymmetric, isopolar; tricolporate, colpae long and not
reaching the poles; usually subprolate, but occasionally prolate spheroidal; amb trilobate; exine c. 2
pm thick, with minutely reticulate texture (oil immersion); 17-20 x 13-18 pn. Figure 4. A, polar; B &
C, equatorial views.
Senna glanduligera (H. St John) A. C . Smith - radiosymmetric, isopolar; tricolporate, poles rounded
almost reached by the colpae, the borders of each colpa distinctively constricted in polar view and
bulging when seen in equatorial view, pores very narrow; subprolate; amb trilobate; distinct opaque
body present on all grains examined, which is resistant to acetolysis; exine c. 2 pm thick, apparently
double, with a granular texture; 27-29x22-25 pm. Figure 5. A, polar and B, equatorial views.
Geniostoma hendersonense H. St John
Heteropolar, mostly tri - or tetrapolar; pores only rarely in an
equatorial plane; pores c. 3 pm in diameter, very prominent owing to the occurrence of heavy exinous
thickenings round each (about 4 pm high), which in cross-section are shield-like; oblate or sub-oblate;
exine c. 1.5 pm thick, with minutely reticulate texture just visible; 13-20 x 18-23 pm. Figure 6,
equatorial view.
Myrsine hosakae H. St John - radiosymmetric, isopolar; tetracolp(or)ate, colpae straight, c. 11 pm long,
occasionally somewhat indistinct; cross-wise arrangement of colpae in polar view very distinctive, pores
only rarely distinct; mostly prolate spheroidal, poles markedly flattened; amb quadrangular in outline;
exine c. 1 pm tliick; 19-23 x 15-22 pm. Figure 7. A, polar and B, equatorial views.
Peperomia hendersonensis Yuncker - inaperturate, apolar; spheroidal; exine c. 1 pm thick, intectate,
verrucate (verrucae up to 1 pm in diameter); 11-15 pm in diameter. Figure 9.
Cyclophyllum barbatum (J. G. Forster) Halle & Florence radiosymmetric, isopolar; tricolporate, colpi
short, broad and shallow, producing distinct notches in polar view; pores distinct, rounded, c. 6 p
in diameter, each surrounded by a distinct thickening 3 pm thick in surface view; oblate, often suboblate; amb rounded to subtriangular; exine c. 2.5-3 pm thick; perreticulate; heterobrochate, brochi
generally 3-4 pm long, some up to 6 pm in length, tending to get smaller towards pores; 30-40 x 4046 p.Figure 8. A, polar and B, equatorial views.
Santalum insulare var. hendersonense (Skottsberg) Fosberg & Sachet radiosymmetric, isopolar; triporate,
pores large, conspicuous, c. 4 pm in diameter, tending to elongate meridionally, bordered by meridional
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116
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J. FLORENCE ETAL.
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FLORA OF THE PITCAIRN GROUP
117
costae which arch into the intercolpia; subprolate, polar area domed, amb subtriangular; exine c. 1
pm thick, reticulate in an equatorial band, becoming perforate and ultimately psilate in the polar areas
of the hemispheres, reticulation heterobrochate, brochi < 1 pm across, 25-30 x 21-23 pm. Figure 10.
A, polar; B & C, equatorial views.
Nesoluma st.-johnianum Lam. & Meeuse material obtained was sterile.
-
REFERENCES
Erdtman G. 1943. An introduction to pollen analysis. Waltham: Chronica Botanica.
Faegri K, Iversen J. 1964. Textbook of pollen analysis. Copenhagen: Munksgard.
APPENDIX 2: THE LICHENS OF HENDERSON ISLAND AND OENO ATOLL,
A PRELIMINARY SURVEY
Prepared by S. Waldren and D. Galloway (The Natural History Museum, Cromwell Road, London
SW7 SBD, U.K.).
A collection of 78 numbers from Henderson Island and 27 numbers from Oeno Island was made by
the senior author in 1991 and forms the basis of the annotated list which is presented below. The
collection is still not completely identified and the resulting list is therefore incomplete. We list the
identifications made to date below, with notes on their hosts and distribution where available. Vouchers
are located at BM with duplicates at TCD.
Henderson Island
?
Buellia ghucotheca (Fée) Malme
Known from the West Indies and South America. A single record from the plateau forest along
the Pinnacle trail, on Pisonia grandis: SW91-28 (part)
Caloplaca cf granulosa (Müll. Arg.) Jatta
Known from the British Isles, south and central Europe, North America and North Africa (Purvis
et a l , 1992). On coastal A r p i a , SW91-134
Chrysothrix candelaris (L.) Laundon
Cosmopolitan. Occasional on Pandanus, North Beach forests; not seen elsewhere. SW91-51
Coccocarpia palmicola (Sprengel) L. Arvidss & D. J. Galloway
Only seen in the plateau forests. A common pantropical species, widely distributed in the Pacific
(Arvidsson, 1982). SW91-115, SW91-120
Collema kauaiense H. M a p .
Common on coastal A r p i a , fairly common in plateau forests. SW91-124, SW91-128a (part),
SW91-146, SW91-158 (part)
Collema japonicum (Miill. Arg.) Hue
Plateau forest, in heavy shade. SW91-111
Dirinaria applanata (Fée) Awasthi
Widespread epiphyte, generally in lightly shaded conditions. SW91-42, SW91-141 (part)
Dirinaria conjuens (Fr.) Awasthi
In beach and plateau forests, often on Cordia and Pisonia. SW91-55, SW91-119, SW91-128,
SW91-136
Dirinaria picta (Sw.) Clements & Shear
’ In similar locations to D. applanata, but commoner. SW91-27, SW91-39, SW91-117, SW91-141
(Part)
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Figures 1-10. Photomicrographs of pollen from endemic Henderson Island taxa. Fig. 1, Alyxia
sp.; Fig. 2, Bidens hendersonensis var. hendersonensis (polar); Fig. 3, Glochidion pitcairnense (left:
polar; right: equatorial); Fig. 4, Xylosma suaueolens subsp. haroldii (left: polar; right: equatorial);
Fig. 5, Senna glanduligera (left polar; right: equatorial); Fig. 6, Geniostoma hendersonense
(equatorial); Fig. 7, Myrsine hosakae (left: polar; right: equatorial); Fig. 8, Cyclophyllum barbatum
(left: polar; right: equatorial); Fig. 9, Peperomia hendersonensis, Fig. 10, Santalum insulare var.
hendersonense (left: polar; centre & right: equatorial).
118
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J. FLORENCE ETAL
Hypotrachyna minarum (Vainio) Krog & Swinsow
Widespread in temperate and tropical lowlands. Noted from beach and plateau forest, often on
Pandanus. SW91-54, SW91-112, SW91-155 (part)
Hypotrachyna cf. rachista (Hale) Hale
On coastal Pandanus. Known from southern N. America, Central and South America (Hale,
1975). SW91-155
Parmeliella mariana (Fr.) Jarg. & Gall.
Common and locally abundant in plateau forests, especially on Xylosma, but also common on
Pisonia and Glochidion; occasional in embayment forest. A common tropical species, widely
distributed in the Pacific region (Jmgensen’k Galloway, 1992). SW91-113, SWGl-125, SW9i132, SW91-139, SW91-157
Parmotrema saccatilobum (Taylor) Hale
Type collection of this species is ‘Pitcairn’s Island, Beechey’ [FH-Taylor, lectotype]. Known only
from the Pitcairn group, Fiji and the Marshall Islands (Hale, 1965). On Pzionia, only in the
plateau forest. SW91-31, SW91-126
Parmotrenia tincforum (Nyl.) Hale
A common epiphyte throughout plateau and beach forests; not recorded from the southern half
of the island. A common, pantropical weedy species (Hale, 1965; Swinscow & Krog, 1988).
SW91-31, SW91-49, SW91-109
Pertasaria leio$acella Nyl.
Spores 8 per ascus, ovoid, wall 5-7 pm thick, 85-100x31-34 pm. Agrees well with Archer &
Eli’s (1992) description, but spores larger. Only seen in the plateau forests, especially on Pisonia
grandis and Xylosma suaveolens. Known elsewhere only from New Caledonia and Queensland,
Australia. SW9 1-28 (part)
Physa’a tribacia (Ach.) Nyl.
In beach forest on Cordia. A widespread temperate species (Swinscow & Krog, 1988). SW91-55,
SW91-110, SW91-119, SW91-128a
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Physma byrsaeum (Ach.) Tuck.
Local in the plateau and beach forests. A widespread tropical species (Galloway, 1985; Swinscow
& Krog, 1988). SW91-55, SW91-110, SW91-144
Pyxine cocoes (Sw.) Nyl.
On coastal Pandanus and A r p i a . A widespread pantropical species (Awasthi, 1982; Rogers, 1986;
Swinscow & Krog, 1988). SW91-154, SW91-172
Pyxine consocians Vainio
A single record from Pisonia grandis on the N-S trail. A pantropical species known from East
Africa (Swinscow & Krog, 1988); India (Awasthi, 1982) and Australia (Rogers, 1986). SW91-137
Ramalina celastri (Sprengel) Krog & Swinscow
Common in rather exposed locations; found occasionally in the plateau forests, more common
in beach forest at the North Beach. A widespread, pantropical species (Stevens, 1987; Swinscow
& Krog, 1988). SW91-38
fielotrema lacteum Krempelh.
Spores brown, 7-9 septate, 28-38 x 11-14 pm; agrees well with Hale’s (1981) description. A
widely distributed pantropical species (Hale, 1981). Only noted in plateau forest; usually on
Pandanus or Pisonia, but also seen on Xylosma suaveolens. SW91-28 (part), SW91-30 (part), SW91(part) SW91-135
Oeno
Dirinaria applanata (Fée) Awasthi
Common. SW91-174, SW91-182, SW91-194, SW91-200
Dirinaria picta (Sw.) Clements & Shear
SW91-200a, SW91-201
Pyxine cocoes (Sw.) Nyl.
SW91-172 (part), SW91-185
Pyxine consocians Vainio
Probably common, seen in PisonialArgusia forest and in open areas of shrubby Argusia. SW91182 (part)
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FLORA OF THE PITCAIRN GROUP
119
Ramalina nervulsosa var. luciae (Molho et a l ) Stevens
Uncommon, mostly on Pandanus. Known from Sri Lanka, Indonesia, Kenya, Australia, New
Hebrides, Fiji, Cook Islands and Tahiti. SW91-187
REFERENCES
Archer AW, E l k JA. 1992. Further species and new reports of Pertusaria (lichenised Ascomycotina)
from Australia. Mycotaxon, 45: 417-431.
Arvidsson L. 1982. A monograph of the lichen genus Coccocaqbia. Opera Botanica 67: 1-96.
Awasthi DD. 1982 [1980]. Pyxine in India. Plytomoqhology 30: 359-379.
Galloway DJ. 1985. Flora of New Zealand Lichens. Wellington: PD Hasselberg, Government Printer.
Hale ME. 1965. A monograph or Parmelia subgenus Ampliigymnia. Contributions from the United States
National Herbarium 36: 193-358.
Hale ME. 1975. A revision of the lichen genus Hypotrachyna (Parmeliaceae) in tropical America.
Smithsonian Contributions to Botany 25: 1-73.
Hale ME. 1981. A revision of the lichen family Thelotremataceae in Sri Lanka. Bulletin of the British
Museum (Natural History) (Botany) 8: 227-332.
Jsrgensen PM, Galloway DJ. 1992. Pannariaceae. Flora of Australia 54: 246-293.
Purvis OW, Coppins BJ, Hawksworth DL, James PW, Moore DM. 1992. í7ze Lichen Flora of Great
Britain and Ireland. London: Natural History Museum Publications.
Rogers RW. 1986. The genus Pyxine (Physciaceae, lichenised Ascomycetes) in Australia. Australian
Journal of Botany 34.: 131-154.
Stevens GN. 1987. The lichen genus Ramalina in Australia. Bulletin of the British Museum (Natural
History) (Botany) 16: 107-223.
Swinscow TDV, Krog E. 1988. Macrolichens of East Africa. London: British Museum (Natural History).