Description from Flora of China
Illigera grandiflora var. microcarpa C. Y. Wu; I. grandiflora var. pubescens Y. R. Li; I. villosa C. B. Clarke f. subglabra Kubitzki.
Lianas, 2-6 m tall. Stem angulate, yellow-brown villous especially near buds, occasionally glabrous. Leaves 3-foliolate; petiole 4-12 cm, densely yellow-brown villous; leaflets: petiolules 0.5-2 cm, densely hispid; blade ovate or obovate to lanceolate-elliptic, 4-14 × 3-9 cm, papery to subleathery, abaxially glabrous or sparsely villous on midvein at base otherwise glabrous, adaxially sparsely hispid especially on midvein, occasionally glabrous, lateral veins 4- or 5-paired, raised on both surfaces, veinlets inconspicuous, base subrounded to oblique, apex shortly acuminate to mucronate, rarely subobtuse. Cymes axillary, compact, shorter than leaves, or in a panicle subequal to leaves; rachis and peduncle densely yellow-brown pubescent. Flowers red, purple-red spotted or purple-red striate. Outer tepals oblong, 1.2-1.4 cm, adaxially pubescent, 5-veined. Inner tepals similar to outer ones but smaller, 3-veined. Stamens ca. 8 mm; filaments straight in bud, pubescent; appendages stipitate, narrowly ovate, 3-4 mm, membranous, abaxially with open mouth, margin dentate or entire at apex. Ovary ± tetragonous, densely pubescent or hispid; style 0.8-1.3 cm, villous. Interstaminal glands small, 2-lobed. Fruit (2-)4-winged; large wings (2.5-)3-4 cm wide, smaller ones narrower. Fl. Jun-Aug, fr. Aug-Oct.
The roots and stem are used medicinally for treating traumatic injuries.
Illigera grandiflora was reduced to the synonymy of I. villosa C. B. Clarke by Kubitzki (Bot. Jahrb. Syst. 89: 171. 1969). However, according to the description of I. grandiflora and the amended description of I. villosa by Fischer (Bull. Misc. Inform. Kew 5: 212. 1939), the latter species is quite different from I. grandiflora. Illigera villosa is characterized by its inflorescence being corymbose, flowers smaller, outer tepals 7-8 mm, inner tepals 6-6.5 mm, stamens ca. 4 mm, filaments robust, and appendages ellipsoid and obtuse at the apices.
Forests; 800-2100(-3200) m. S Guizhou, S Yunnan [India, N Myanmar].