Description from Flora of China
Nauclea formosana Matsumura; Ourouparia hirsuta (Haviland) Yamamoto; Uncaria formosana (Matsumura) Hayata; U. kawakamii Hayata; U. uraiensis Hayata.
Lianas, height unknown. Young stems slender, terete or weakly 4-angled, sparsely to densely strigillose, strigose, or hirsute. Petiole 3-6 mm, strigose to strigillose; leaf blade drying thickly papery to thinly leathery, ovate, lanceolate-oblong, or elliptic, 8-12 × 3.5-7 cm, adaxially glabrous and smooth to sparsely puberulent-scabrous on lamina and puberulent on veins, abaxially sparsely to densely strigose with trichomes generally produced regularly along and at 90° to tertiary veins, apex acuminate; secondary veins 7-11 pairs, usually with hirtellous domatia; stipules generally deciduous, broadly ovate, 7-10 mm, 2-lobed for at least 2/3, strigillose, puberulent, or glabrescent, lobes ovate to lanceolate, ciliate, acute to acuminate. Inflorescences axillary or frequently paired and terminal on stems (apparently due to terminal bud not developing further), pilose to pilosulous; peduncle 2.5-5 cm, simple; bracts 5-10 mm; flowering heads 18-25 mm in diam. across calyces, 30-40 mm in diam. across corollas; bracteoles linear or spatulate, ca. 2 mm. Flowers subsessile. Calyx with hypanthium portion obconic, ca. 2 mm, densely pilose to strigose; limb densely strigillose, with tube 2-4 mm; lobes linear-oblong, 2-3 mm. Corolla pale yellow or pale red, salverform, outside sparsely to densely strigillose; tube 7-10.5 mm; lobes oblong to elliptic, 2-2.5 mm, obtuse to rounded. Fruiting heads 30-35 mm in diam. Fruit subsessile, obovoid, 5-9 mm (not including persistent calyx limb), densely strigose; seeds ca. 1.5 mm. Fl. and fr. Jan-Dec.
H. H. Hsue and H. Wu (in FRPS 71(1): 257. 1999) listed "Ourouparia setiloba Sakai" as a synonym of this species, but that name is correctly "Ourouparia setiloba (Bentham) Sakai," which is a combination based on Uncaria setiloba, here treated as a synonym of U. lanosa var. appendiculata. Hsue and Wu described the corolla tubes as 7-10 mm, but these are 8-10.5 mm on all the specimens studied and in descriptions of other authors.
● Thickets or forests at streamsides in valleys; below 100-500 m. Fujian, Guangdong, Guangxi, Guizhou, Taiwan.