4. Uncaria lancifolia Hutchinson in Sargent, Pl. Wilson. 3: 407. 1916.
倒挂金钩 dao gua jin gou
Large lianas, height unknown. Young stems quadrangular, glabrous. Petiole 3-5 mm, glabrous; leaf blade drying papery, oblong-lanceolate or ovate-lanceolate, 9-12 × 3-6 cm, glabrous on both surfaces, base rounded to truncate or subcordate, apex acute or acuminate; secondary veins 5-10 pairs, without domatia; stipules often persistent, ovate, 5-8 mm, 2-lobed for 1/3-1/2, glabrous, lobes lanceolate, acute. Inflorescences axillary and terminal, glabrous; peduncles 4-7 cm, simple; bracts caducous, ca. 5 mm; flowering heads ca. 15 mm in diam. across calyces, ca. 45 mm in diam. across corollas; bracteoles linear or linear-spatulate, 3-4.5 mm. Flowers sessile. Calyx with hypanthium portion obconic, ca. 3 mm, densely sericeous to pilose; limb densely puberulent to strigillose, with tube 1-2 mm; lobes spatulate, ca. 2 mm, obtuse to rounded. Corolla greenish white, salverform, glabrous; tube 9-12 mm; lobes oblong, 1.5-2.5 mm, obtuse to rounded. Fruiting head 25-35 mm in diam. Fruit sessile, obovoid, 9-12 mm, sericeous to strigose; seeds 2.5-3 mm. Fl. and fr. Jun-Dec.
Subtropical evergreen broad-leaved forests; 1500-1900 m. Yunnan [Vietnam].
How (Sunyatsenia 6: 252. 1946) first described the flowers of this species. H. H. Hsue and H. Wu (in FRPS 71(1): 253. 1999) described the leaves as having domatia; but the type specimen and several additional specimens studied lack these, and How did not mention them.