Description from Flora of China
Oldenlandia ampliflora (Hance) Kuntze.
Herbs or shrubs, perennial, lianescent, clambering, twining, or scandent, to perhaps 1 m; stems flattened to subterete, smooth to sulcate, densely hirtellous or pilosulous throughout or in lines, to glabrescent. Leaves petiolate; petiole 2-6 mm, densely hirtellous to puberulent; blade drying papery, lanceolate, broadly lanceolate, elliptic, or narrowly elliptic, 2-7 × 0.8-3 cm, adaxially hispidulous or strigillose along midrib to throughout, abaxially hispidulous or hirtellous to glabrous, base cuneate to obtuse, apex acute or shortly acuminate; secondary veins 3 or 4 pairs; stipules fused to petiole bases, densely hirtellous to hispidulous, sheath portion 1-3 mm, truncate to triangular, apex lacerate into 3-5 narrowly triangular to linear bristles or lobes 1-6 mm. Inflorescences terminal and occasionally also in axils of uppermost leaves, compound-cymose, corymbiform, 3-12 cm, several to many flowered, densely to sparsely hirtellous to puberulent, pedunculate; peduncles 1-3.5 cm; axes dichotomous, spreading; bracts triangular, lanceolate, or narrowly elliptic, 1-7 mm; pedicels 1-3.5 mm. Flowers pedicellate, apparently distylous. Calyx glabrous to densely hirtellous; hypanthium portion subglobose or turbinate, 0.8-1 mm; limb lobed for 3/4-4/5; lobes lanceolate to spatulate, 1.2-1.8 mm, acute, usually spreading to reflexed. Corolla white or greenish white, tubular to salverform, outside granular-puberulent; tube ca. 1 mm, barbate in throat; lobes lanceolate to spatulate, 2-2.5 mm, acute. Anthers partially or long exserted, 0.8-1 mm. Stigmas in short-styled form not seen, or exserted and ca. 0.3 mm. Fruit capsular, subglobose to ovoid, sometimes slightly flattened, 2.5-3 × 2-2.5 mm, glabrous to densely hirtellous, cartilaginous to stiffly papery, loculicidal then septicidal across top then tardily along sides, beak conical, ca. 1 mm; seeds numerous, blackish brown, angled. Fl. May-Nov, fr. Oct-Nov.
The Kew Rubiaceae checklist (Govaerts et al., World Checkl. Rubiaceae; http://www.kew.org/wcsp/rubiaceae/; accessed on May 2007) reports this species also from Vietnam; it is not listed in the Vietnam checklist.
● Sparse forests or thickets on mountain slopes; 100-400 m. Hainan.