拟定经草 ni ding jing cao

Oldenlandia brachypoda Candolle, Prodr. 4: 424. 1830.

Slender herbs, annual, diffusely branched, to 50 cm tall; stems terete to slightly flattened, glabrous. Leaves sessile or subsessile; blade drying membranous, linear, narrowly elliptic, or narrowly spatulate, 7-36 × 1-4 mm, adaxially glabrous (sometimes appearing papillose due to collapsed, large epidermal cells) to scaberulous and usually shiny, abaxially glabrous and matte, base acute, margins usually revolute at least when dry, apex acute; secondary veins not evident; stipules fused to petiole bases, glabrous, truncate to broadly triangular, 0.8-2 mm, with 1-3 linear to setiform lobes 0.2-1 mm. Inflorescences pseudoaxillary, 1-flowered (2-flowered and fasciculate), glabrous, sessile or with peduncle to 3 mm, ebracteate. Flowers subsessile to shortly pedunculate, homostylous. Calyx glabrous; hypanthium portion globose, 1-1.2 mm; limb lobed essentially to base; lobes triangular, 1-1.5 mm. Corolla white, rotate, outside glabrous; tube 1-1.5 mm, glabrous at throat; lobes triangular, 1-1.5 mm. Anthers ca. 0.3 mm, exserted. Stigma ca. 0.8 mm, exserted. Fruit capsular, membranous to papery, compressed globose to subglobose or somewhat dicoccous, ca. 2.5 × 3-4 mm, loculicidally dehiscent through flattened top, peduncles to 8 mm; seeds ca. 20, dark brown, angled, deeply and thickly foveolate. Fl. and fr. (Feb-)Mar-Nov.

Paddy fields, ridges of farmlands, humid open fields; below 100-1500 m. Anhui, Guangdong, Guangxi, Hainan, Yunnan [Bangladesh, Bhutan, India, Indonesia, Japan, Malaysia (Malacca), Nepal, Philippines, Vietnam].

The taxonomy of this and related species is complicated, and different authors have drawn very different conclusions (e.g., Sivarajan & Biju, loc. cit.: 665-674; Dutta & Deb, Taxon. Rev. Hedyotis. 2004). In particular, Hedyotis corymbosa, H. diffusa, and H. erecta Manilal & Sivarajan are related and have been variously circumscribed. Here, these species are circumscribed generally, though not completely, following Sivarajan and Biju (loc. cit.) and W. C. Ko (in FRPS 71(1): 72, 75. 1999).