Cynanchum callialatum Buch.-Ham. ex Wight

Global description

Cynanchum callialatum is an annual twining vine that can measure 3m long. It emits a white latex. The stem is cylindrical. The leaves are opposite, simple, stalked, blade ovate to oblong, 4.5 to 8 cm long, fleshy, glabrous. The base is cordate, the top acuminate and margin entire. The inflorescence in the axils of leaves form a shortly stalked pseudo-umbel, consisting of 6 to 12 whitish flowers with the calyx formed of 5 oblong greenish sepals and the corolla fused to the base and then spreading into 5 petals oblong of 4 mm long reddish green in colour. At the center of the corolla is a white membranous ring with 5 linear lobes of 4 mm. The fruit is a follicle with 2 loculus, oblong to lanceolate, 5 to 8 cm long and 1.5 cm in diameter, with two prominent wings at the top. The seeds are ovate 5 mm long, extended by long white bristles of 2 cm.

General habit

Cynanchum callialatum is an annual species growing as twinning vines that wraps around supports. It can measure up to 3 m long.

Underground system

The plant has a taproot system.

Stem
 
The stem is cylindrical, full. It produces a white latex when cut. It is fleshy, with smooth and glabrous surface, except for a line of hair.
 
Leaf
 
The leaves are simple, opposite, held by a petiole 1 to 4 mm. The lamina is oval to oblong, 4.5 to 8 cm long and 2-4 cm wide, thick and fleshy. The base is cordate, the apex acuminate into a short, wide tip and the margin is entire, sometimes slightly revolute. Both sides are glabrous. The upper side is bright green, the underside is murky green. The leaf blade is trinervate at the base and covered with 6-12 pairs of pinnate veins.

Inflorescence

On the inflorescence is a pseudo-umbel, located in the axils of leaves and held by a stalk of 1 to 7 mm long. It has 6-12 flowers.

Flower

Each flower is carried by a pedicel of 3 to 6 mm. It consists of a calyx with 5 lanceolate sepals, 2 to 2.5 mm long and 1 mm wide, of a corolla fused in a basal tube of 1 mm then 5 spreading lobes, oblong lanceolate, 4mm long and 1.5 to 2 mm wide, reddish green in color. At the center of the corolla is an erect membranous crown, white, 3.5 mm, with 5 linear lobes with a small tine between each lobe or reduced to a ring. The anthers are 1mm. The stigma is ovoid, leaving the crown.

Fruit

The fruit consists of two follicles with usually one of the two aborted. The remaining follicle is oblong lanceolate, 5 to 8 cm in length and 1 to 1.5 cm in diameter, having two wings at the end. At maturity, it opens longitudinally. It contains many seeds.

Seed

The seed is oblong oval, flattened, 5 mm long and 3 mm wide, with a tuft of long white bristles of 2 cm on the top.

https://www.gbif.org/species/7740696