Ipomoea obscura (L.) Ker Gawl.

Global description

Ipomoea obscura is a twining herbaceous vine, climbing, sometimes trailing, 2 to 3 m long. The stem is cylindrical, slender, glabrous or covered with long dense hairs. The leaves are alternate, simple, entire, broadly ovate to subcircular, with the base deeply cordate and the apex tapered in a point. The faces are almost glabrous, the margin is slightly ciliated. The flowers are solitary or by 2 on top of a long slender peduncle. They look like little trumpets, very flared and cream white in colour. The globular fruit is dry, containing 4 gray seeds. It remains surrounded at the base by the persistent calyx.
 
Cotyledons
 
The cotyledons are stalked, with a petiole of 1.5 cm long. The lamina is distinctive, elongated rectangular in shape, 2 cm long and 1.5 cm wide, with truncate base and notched summit till the base, completely separating the lamina in 2 distinct linear lobes, with asymmetrical base. The stem is marked by two palmate-veins, emerging from the base of each lobe and climb to almost the top.
 
First leaves
 
The first leaves are simple, alternate, with a long stalk. The petiole is pubescent to hairy. The leaf blade is broadly ovate, 3 cm long and 2.5 cm wide, with cordate base and wide apex. The margin is entire, finely ciliated and both sides of the leaves are sub-glabrous.
 
General habit
 
Herbaceous plant, twining, creeping or climbing, measuring 2 to 3 meters long.
 
Underground system
 
The plant has a taproot system.
 
Stem
 
The stem is cylindrical, solid, twining, 1 to 2 mm in diameter, sub-glabrous to hairy, and measuring 2 to 3 m long.
 
Leaf
 
The leaves are simple, alternate, held by a petiole of 1.5 to 3 cm long with a retrorse pubescence. The leaf blade is entire, broadly oval to sub-circular, 3 to 9 cm long and 2.5 to 8 cm wide. It is deeply cordate at the base, apiculate and mucronate at the apex. The margin is entire, finely ciliated, both sides are glabrous to finely pubescent. The main venation is palmate with 5-9-veins emerging from the base.
 
Inflorescence
 
The inflorescence is axillary, at the end of a long stalk, 1 to 5 cm, with retrorse hairs, with 1 to 2 flowers.
 
Flower
 
Each flower is held by a slender pedicel, 1.5 to 2 cm long, hairy, at the base of which is a small bract, 2 to 4 mm. The calyx consists of 5 free sepals, ovate, mucronate, 3 to 5 mm long. The corolla is formed of five petals, fused into a narrow tube which is then widely flared, 1.5 to 2.5 cm long and 2 cm in diameter. It is creamy white, sometimes purple in center. The five stamens and pistil are included in the corolla tube.
 
Fruit
 
The fruit is a globular capsule, smooth, light brown in color, 6 to 10 mm in diameter, apiculate, surrounded by persistent calyx, with 2 loculus and 4 valves. It contains 4 seeds.
 
Seed
 
The seed is subtrigonal, 3.5 to 4.5 mm long, gray with dark seed coat, with dense velvety pubescence.

Origin

Ipomoea obscura is native to Central, Eastern and Southern Africa, the Indian Ocean islands, India and Asia.

Worldwide distribution

This species has been introduced in the Caribbean, the West Indies, Australia and the Pacific Islands (New Caledonia, Marianas, Marquesas, Tuamotu, Hawaii).

https://www.gbif.org/fr/species/2928565