The five-fingered yam, Dioscorea pentaphylla, was one of the "canoe plants" carried by the first Polynesians from Southeast Asia and "Near Oceania" westwards. As a food item it has been largely replaced by the purple yam, ufi (Dioscorea alata, u'i in Rarotonga and uhi or uwhi in Aotearoa), also an early Polynesian introduction, but it was retained and cultivated as a famine food. In Tahiti the name pirita was applied to the spiny yam, Dioscorea nummulata, another canoe plant known as palai in Samoa and u'i parai in the Cook Islands. In Rarotonga the meaning of the word was expanded to include a species of jasmine used in weaving, and another vine.
In Aotearoa, where if Dioscorea pentaphylla was introduced it did not thrive, the word was used to name a formidable forest liane, and a group of mistletoes. These are described on the page for the Māori word Pirita.
The Five-Fingered Yam, Dioscorea pentaphylla
 Dioscorea pentaphylla stands out from the other varieties of yam grown in Polynesia with its compound leaves in contrast to the simple, heart-shaped leaves of the other species. It is native to tropical Asia but was spread throughout Polynesia except Aotearoa. The plant puts out its stems each year; it generally has a single tuber, which may be near the surface or a metre or more below ground. The stems are slightly hairy, with few if any prickles except sometimes at the base (where at least in Hawai'i they can be quite prickly). The stems twine to the left (counter-clockwise), and can reach 10 m or more in length. The leaves have 3, 5 or 7 leaflets, with the central one larger than the others; they are yellowish brown when young, but often turn purple when about to fall off. The largest leaf can range fron 7-15 cm long by 3-5 cm wide. Globular bulbils, about 1 cm in diameter, and occasionally small horse-shoe shaped tubers occur in the axils of the leaves. The plant seldom flowers in the Cook Islands so there these bulbils and mini-tubers are its main means of reproduction. It does flower elsewhere, however. The tiny greenish male and female flowers are borne on separate spikes. The oblong fruit is about 2 cm long; both the fruit (illustrated above, left) and seeds are winged.
The plant grows best in moist conditions. In the Marquesas it is found in valleys in moist or wet forests from 100 to 700 m, and in Hawaii in moist valleys from 115-325 m on the windward side of most islands. In the Cook Islands it is found mainly in disturbed forests.
The white tubers are considered to have an inferior taste so it is primarily an emergency food. It is not sticky enough for easy mashing; in Hawai'i it was cooked in chunks in an umu.
Dioscorea nummularia, the Spiny-base Yam
This species is known as pirita only in Tahiti; elsewhere where it has been established in Polynesia it is generally known as palai or (uhi) parai. Art Whistler (Plants of the Canoe People, p. 103) considered it to have been an ancient introduction in Western Polynesia, but a relatively recent arrival in Eastern Polynesia. It is native to the Philippines, Borneo and New Guinea.
The stems are spiny, grow to about 10 m in length, and twist to the right (clockwise). The leaves are simple and heart-shaped, varying from 2 by 5 cm to 9 by 15 cm, usually arranged opposite in pairs but sometimes alternating on longer stems. The plants are are unisexual -- male plants bear only male flowers and female plants bear only female flowers. The flowers are small and pale green or whitish. Female flowers are borne in clusters on long spikes, and male flowers in whorls on short spikes. The fruit is a brown winged capsule with winged seeds.
The plant does not spread readily in the wild. In the Cook Islands (where it is known as u'i parai) it is classified as nationally critically endangered. The tubers lie deep in the soil and are difficult to dig out, so are collected mainly in times of famine. In earlier times it seems to have been an important food item generally in Western Polynesia with the tubers left to grow for several years before harvesting. It is prepared for baking or boiling like taro, and sometimes cooked in coconut cream.
Gynochthodes myrtifolia, the Pirita tutae puaka
 Gynochthodes (formerly Morinda) myrtifolia is not a yam, although known as Pirita tutae puaka in Rarotonga. It is a member of the coffee family (Rubiaceae), and related to the famous noni shrub. However it is a yam-like climber and scrambler, and the odd-shaped knobbly ovaries and fruit are reminiscent of both both miniature yams and pig droppings, hence its full name.
The plant originated in New Guinea but is found natively in many parts of Polynesia, including the Cook Islands, where it is common in the forests from sea level to about 500 metres.
It does not climb as high as the Dioscorea yams. It has variable, elongated tapering leaves with pointed or rounded tips, ranging from 4 to 11 cm long by 1.5 to 5 cm wide, glossy deep-green above with the margins wavily toothed. The female flowers (illustrated, greatly enlarged, opposite) protrude from the rather weird syncarp (a kind of compound ovary).
William Sykes (Flora, p. 819) comments that "Unlike nono [Morinda citrifolia] pirita tutae puaka has few if any uses; indeeed, this Cook Islands name, meaning pig excrement pirita, suggests that it is not valued."
Pirita as Jasminum didymum ssp. didymum
 This very useful plant is native to Southeast Asia and Northern Australia, and has spread naturally eastward as far as the Society Islands. It is known as 'Āketa on Rarotonga but Pirita on the outer islands, where its stems are used for making 'inaki (hinaki -- eel and fish traps) like its namesake in Aotearoa, along with baskets and trays. Kiekie (Freycinetia wildii) and coconut roots are used for these purposes elsewhere. Art Whistler (Plants of the Canoe People p. 391) notes that according to Davies' Dictionary (1851) in Tahiti Pirita also refered to the root of the kiekie, used to make fish traps.
The vine has a tough stem and leaves consisting of 3 leaflets on a stalk up to 4cm long, the terminal leaflet up to 8 cm long by 4 cm wide, tapering at the tip, on a stalk about 1.5 cm long, and the paired lateral ones slightly smaller on a stalk about half that size.
The fragrant white flowers are followed by glossy black berries about a centimetre in diameter, often produced in pairs.
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