黄花小二仙草 huang hua xiao er xian cao

Gaura chinensis Loureiro, Fl. Cochinch. 1: 225. 1790; Gonocarpus scaber K. D. Koenig; G. tetragynus Labillardière; Haloragis chinensis (Loureiro) Merrill; H. chinensis var. yapensis Tuyama; H. scabra (K. D. Koenig) Bentham; H. scabra var. elongata Schindler; H. scabra var. novaguineensis Valeton; H. tetragyna (Labillardière) J. D. Hooker; H. tetra gyna var. micrantha Bentham.

Herbs perennial, erect or ascending, 10-60 cm tall. Stem weak, 4-ribbed, scabrous with sparse appressed hairs. Leaves decussate, becoming alternate near inflorescence, sessile or subsessile; leaf blade linear-lanceolate, oblong, or linear, 10-28 × 1-9 mm, surfaces scabrous, base rounded, margin thickened, serrate with 15-30 small teeth, apex obtuse. Inflorescence an indeterminate spike, branched; bracts leaflike, lanceolate to narrowly ovate, 0.5-1.5 × 0.3-0.5 mm, adaxially pubescent, margin thickened, entire; bracteoles brown, linear to lanceolate, 0.2-0.5 mm, membranous. Flowers erecto-patent, 4-merous; pedicel ca. 0.2 mm. Sepals green, triangular, 0.6-0.9 × 0.4-0.5 mm, glabrous, with a small, median-basal callus, margin thickened. Petals yellow, sometimes reddish, hooded, very shortly clawed, 1-1.5 × 0.3-0.5 mm, sparsely hirsute on keel. Stamens 8, ca. 1 mm. Ovary 4-loculed; styles clavate, 0.1-0.3 mm; stigmas reddish, capitate, fimbriate. Fruit silver-gray to dark gray, broadly ellipsoid, 0.7-1 × 0.8-1 mm, weakly 4-angled or 8-ribbed, with up to 2 oblique calluses between ribs, scabrous, with short, curved, appressed hairs confined almost entirely to ribs. Seed 1 per fruit. Fl. Mar-Oct, fr. May-Nov.

Open grasslands, waste land, river banks, deforested slopes; 100-800 m, to 1500 m in SW China. Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Yunnan, Zhejiang [Indonesia, Malaysia (Sabah), Papua New Guinea, Philippines, Singapore, Vietnam; SW Asia (W Iran), N and W Australia, Pacific islands (Caroline Islands, introduced in Hawaii)].

Chinese plants belong to Gonocarpus chinensis subsp. chinensis, whereas subsp. verrucosus (Maiden & Betche) Orchard (Haloragis verrucosa Maiden & Betche) is found along the coastal regions of New South Wales and Queensland. The fruit of the latter taxon have papillae (never calluses) on and between the ribs and are always globular.