4. Leptopus clarkei (J. D. Hooker) Pojarkova, Bot. Mater. Gerb. Bot. Inst. Komarova Akad. Nauk S.S.S.R. 20: 272. 1960.
缘腺雀舌木 yuan xian que she mu
Andrachne clarkei J. D. Hooker, Fl. Brit. India 5: 285.1887; A. attenuata Handel-Mazzetti; A. attenuata var. microcalyx Handel-Mazzetti; A. esquirolii H. Léveillé; A. esquirolii var. microcalyx (Handel-Mazzetti) Rehder; A. hypoglauca H. Léveillé; A. persicariifolia H. Léveillé; Leptopus attenuatus (Handel-Mazzetti) Pojarkova; L. esquirolii (H. Léveillé) P. T. Li; L. esquirolii var. villosus P. T. Li; L. kwangsiensis Pojarkova.
Procumbent to ascendent herbs to subshrubs, up to 1.5 m tall, monoecious. Branchlets longitudinally strongly ribbed, white to light green, rarely reddish. Stipules triangular, base not auriculate, apex acute, ferruginous; petiole 1.5-10 × 0.4-0.7 mm; leaf blade ovate to lanceolate, (1.5-)2-6.5(-10) × (0.8-)1-2(-3) cm, papery, sometimes membranous, drying concolorous to slightly discolorous light whitish green to yellowish or grayish light green, abaxially glabrous to sparsely hirsute, adaxially glabrous, base rounded, sometimes obtuse, rarely acute, apex acuminate; secondary veins 3-6 pairs, sometimes not visible. Inflorescences unisexual or bisexual, male inflorescence axis 0-0.1(-3) mm. Male flowers 1-3 per fascicle, 2-4 mm in diam.; pedicel 5-17 mm; sepals obovate to oblong, apex rounded, 1.2-3 × 0.7-1.4 mm, eglandular; petals obovate, apex rounded, 0.8-1.5 × 0.25-1 mm; disk bilobed for 4/5-5/6 of length. Female flowers 1-2 per fascicle, 2.5-6 mm in diam., mostly narrowly cupular; pedicel 10-20 mm; sepals ovate to elliptic, 1.5-5 × 0.7-1.8 mm, apex acute to acuminate, eglandular; petals obovate, 0.2-0.5 × 0.2-0.3 mm, apex rounded; disk bilobed for 3/4 of length; ovary 3-locular, glabrous to sparsely hirsute; styles 3, glabrous. Fruiting pedicel 14-35 mm; sepals not accrescent; capsule smooth to faintly reticulate, glabrous to sparsely hirsute, drying red-brown to brown. Seed smooth, orange to brown.
Mixed forest understories on sand, granite, or limestone; 500-2500 m. Guangxi, Guizhou, Sichuan, Yunnan [India (Assam), Myanmar, Vietnam].
Leptopus clarkei is an ascending creeper. Plants of this species have a lax habit, generally with longer thinner sepals and acuminate leaves. Leaf size, sepal size, and indumentum all vary.
The distinction between Leptopus clarkei and L. esquirolii has caused much confusion, partly due to inaccessibility of type specimens. Type collections of both names are strikingly similar in their habit and long-acuminate, papery leaf blades. Accordingly, L. clarkei and L. esquirolii are here considered conspecific.