About Cynanchum thesioides (Freyn) K.Schum.
Cynanchum thesioides is a perennial suffrutescent, sometimes lianescent herb. It is usually densely shortly pubescent throughout and has white latex. It grows from a monopodial, slightly woody, creeping, slender brown rhizome up to 3 m long and 3 mm thick, with wiry horizontal offshoots. The stem and branches can be straight or twining above. Straight stems are 10 - 40 cm long, erect or ascending, simple or much divaricately branched from the base, with internodes 2 - 30 mm long. Twining stems can reach up to 2 m long, are little branched, and have internodes 4 - 8 cm long. Leaves are opposite or sometimes subopposite, rarely 3 - or 4 - whorled. Petioles are 0.5 - 10 (- 12) mm long or subsessile. The leaf blade is green, thin, and can be linear, narrowly lanceolate, oblong - lanceolate, or occasionally broadly lanceolate, measuring 2 - 10.5 x 0.1 - 2 (- 2.3) cm. The apex is shortly acute, obtuse, or acuminate, rarely rounded. The base is slightly oblique, attenuate, cuneate, truncate, or rounded, with colleters at the middle of the leaf base. Margins are entire, ciliolate, and often revolute. The mid - vein is elevated abaxially, and lateral veins are obscure. Both surfaces are densely pubescent, sometimes glabrate, except for the mid - veins on the lower surface. Inflorescences are alongside the leaf axils to terminal, with 1 - 10 fragrant flowers, and are shortly umbel - to raceme - like. Peduncles are 1 - 10 (- 50) x 0.5 - 1.5 mm and puberulent. Pedicels are 1.2 - 10 x 0.2 - 0.6 mm and puberulent. Sepals are about half the length of the corolla, oblong, triangular, or lanceolate, 1 - 2.8 x 0.3 - 0.8 mm, puberulent, ciliate, with an obtuse, acute, or acuminate apex. The corolla is white, greenish - white, or yellow, 3 - 5 x 3 - 8 mm, usually glabrous, sometimes sparsely puberulent on the dorsal surface and inside the tube, rarely densely puberulent on both surfaces. The tube is 0.5 - 1.5 mm long, and the lobes are 4.3 - 5.2 x 0.8 - 1.5 mm, narrowly triangular, lanceolate, oblong, or oblong - ovate, apically twisted clockwise, with an approximately acute or obtuse apex, sometimes retuse. The corona has 5 slightly fleshy lobes partly fused at the bases, is cupular, 0.8 - 1.8 mm long, and can be shorter or longer than the gynostegium. The tube is shorter than the anthers, 0.3 - 0.7 mm long. Lobes are oval, triangular - lanceolate to linear, with erect or incurved apices that are acute, acuminate, obtuse, or rounded, 0.5 - 1.4 mm long. Sinuses between the lobes may or may not have a minute triangular tooth. Follicles are paired or single, ovoid - fusiform, ventricose, 4 - 10 x 0.8 - 2.5 cm, with an obtuse or attenuated apex, smooth or colliculate, and puberulent. Seeds are reddish - brown, 5 - 10 x 3 - 5 mm, with a white coma 1 - 2.4 cm long attached to the micropylar end (Figs 3 - 5).
