Cynanchum szechuanense Tsiang & Zhan

Cynanchum szechuanense is quite variable in the length of corona lobes. Forms with the longest lobes are restricted to W Sichuan but those with short triangular lobes are found throughout the species range. Further studies are needed to show if infraspecific taxa can be recognized.

Plants pubescent or pilose except for corolla. Stems twining, to 6 m, pubescent along 1 side. Petiole 1.5-5.5 cm; leaf blade ovate or triangular-ovate, 3.2-13(-23) × 1.5-8.5
(-13.5) cm, papery, adaxially minutely appressed puberulent, abaxially pubescent on veins, base deeply cordate with basal lobes sometimes incurved and rarely slightly enlarged, apex acuminate; basal veins 5-7, pedate, lateral veins 2 or 3 pairs. Inflorescences long, simple or with short lateral branches; cymules distinct, many flowered, umbel-like or ± contiguous, few flowered, and racemelike; peduncle 4-8(-12.5) cm, rachis 0-7 cm. Sepals lanceolate, ca. 3.5 × 1 mm; basal glands present. Corolla green or white with purple apex, rotate to reflexed, tube short; lobes lanceolate, 3.5-5.5(-6.7) × 1.4-2 mm, glabrous outside, pubescent inside. Corona white, tube cupular, 1.3-2.5 mm high, membranous, margin with 5 main lobes, these triangular to threadlike, 1.2-3 mm, sinuses between these each usually with ca. 3 small rounded teeth, sometimes ± truncate; inner appendages lanceolate to threadlike, as long as or exserted from tube. Anther appendages rounded; pollinia oblong. Stigma head conical. Follicles lanceolate in outline, 7.5-9 × ca. 1.5 cm. Fl. May-Jul.

W Sichuan, Xizang

* Open woodland, climbing over shrubs; 2300-3200 m.

Cynanchum szechuanense var. albescens Tsiang & Zhang.