Merremia dissecta (Jacq.) Hallier f.

Global description

Merremia dissecta has lianescent stems, several meters long. It is a vine with white latex and a bitter almond smell when crushed. The stem, petioles and peduncles are hairy. The leaf has between 5 to 8 deep lobes in the shape of fingers of gloves, lanceolate, themselves lobed. The median lobe is generally larger with a length of 8 cm. The margin is entire or wavy. The flowers are inserted by 1 or 2 on fairly long stalks. The corolla is in the shape of a flared trumpet, white in colour with purple center. The fruit is globular shaped, remains included in the persistent calyx.
 
 
Cotyledons
 
Cotyledons with smooth petiole, long enough, canaliculate on the upper face. The lamina, 3 cm long and 4 cm wide, is bi-lobed, with two rounded and divergent lobes. The notch of the lobes is less than half the length of the cotyledon.
 
First leaves
 
First leaves are alternate, simple, long-stalked. The lamina with 5 lobes, including a large median lobe and smaller lateral lobes. The top of the lobes is acute, and the margin is entire to finely serrated.
 
General habit
 
Lianescent herbaceous plant, very volubile, and the stem can reach 3 m.
 
Underground system
 
The plant has a long taproot system.
 
Stem
 
The stem is cylindrical, solid, ribbed longitudinally, which lignifies at the base. It contains a white latex with a bitter almond odor. It is volubile, with branches of 3 meters long and 5 mm in diameter. It can be glabrous or covered with shaggy hairs.
 
Leaf
 
Leaves are alternate, simple and deeply palmate lobed. They are held by a long petiole often hairy. The lamina is deeply divided almost to the base in 5 to 9 palmate lobes, elliptical in shape. The median lobe is longer than the lateral lobes, measuring 3 to 7 cm long. The top of the lobes is acute or acuminate. The margin is entire or more or less wavy or more or less serrated. . They are intensely hairy at the venation, with long hairs. The lamina is dark green. The main venation is palmate.
 
Inflorescence
 
Flowers are axillary and solitary or can be grouped up to 3.
 
Flower
 
The flowers are held by a peduncle, up to 15 cm long, and then shortly stalked. The calyx is 1 to 1.5 cm long, formed by two outer hairy sepals and 3 inner glabrous sepals. The corolla is campanulate, 3 to 4 cm in diameter, white or slightly yellow in colour. At the bottom of the corolla there are 5 stamens of irregular length. The white anthers twist after releasing pollen. The ovary is bilocular, ending in a bifid stigma.
 
Fruit
 
The fruit is an ovoid capsule, which develops completely hidden by the sepals. Together, they measure 3 cm long and 2 cm wide at the base. The two outer sepals which is completely covered with hairs, cover the series of three internal hairless sepals. Within this set is a dehiscent ovoid capsule, 10 to 18 mm in diameter, smooth and glabrous, which opens longitudinally to release the seeds. At maturity, the sepals open horizontally in a star of 5 to 6 cm in diameter, brown, the center of which the capsule is located. The capsule has two loculus and contains 4 seeds.
 
Seed
 
Seed is ovoid, slightly trigonal, with concave ventral surface. It measures 7 to 9 mm long and 6 to 7 mm wide. The seed coat is smooth and brown.

Origin

Merremia dissecta is native to tropical America and the Caribbean area.

Worldwide distribution

This species is naturalized in West and Central Africa, in Madagascar and the Indian Ocean islands (Reunion, Seychelles), in the Arabian Peninsula, in India in Asia and in Australia. It is absent from Comoros and Mauritius.

https://www.gbif.org/fr/species/3679601