海南青牛胆 hai nan qing niu dan

Deciduous vines, 3-10 m or longer, glabrous. Old stems fleshy, 6-10 mm in diam., with epidermis membranous, glabrous; lenticels first lens-shaped, 2-dehiscent, then rounded, 4-dehiscent, conspicuously protruding. Petiole 3-12 cm, base swollen and geniculate; leaf blade cordate or orbicular-cordate, 11-15 × 9-12 cm, membranous papery, light green when dried, both surfaces glabrous except for dense brownish glandular hairs in abaxial basal vein axils, base cordate, with sinus 1-2.5 cm, lobes rotund, margin entire, apex often cuspidate, palmately 5-veined, reticulation raised on both surfaces. Inflorescences coetaneous with leaves. Male inflorescences pseudoracemose, consisting of small cymes on 1-3 mm peduncles. Male flowers unknown. Female flowers in fascicles of 2-4, rarely solitary; bract subulate-lanceolate, 2-3 mm; sepals 6, outer whorl minute, subdeltoid, 1.2-1.5 × ca. 1 mm, inner whorl broadly ovate-elliptic, 3.5-4 × ca. 2.5 mm, ?slightly extended when blooming; petals 6, narrowly lanceolate, ca. 2 × 0.4 mm, margin not reflexed, apex mucronate; staminodes 6, slightly shorter than petals; carpels 3, ca. 2 mm, stigma large. Drupes red, broadly elliptic, 1.1-1.2 × 7-9 mm; endocarp broadly elliptic, 9-10 mm, convex ridge abaxially conspicuous only at each end, surface sparsely tuberculate, adaxially flattened with an elliptic aperture ca. 3 × 1.5 mm to condyle. Fl. Apr, fr. Jun.

● Open forests. Hainan.

Tinospora hainanensis has been misidentified as T. glabra (N. L. Burman) Merrill (e.g., Forman, Kew Bull. 36: 417. 1981).

An unpublished IUCN list recorded this species as vulnerable: VU(A1c,2c;B2c).