Odontostemma Bentham ex G. Don, Gen. Hist. 1: 449. 1831; Gooringia F. N. Williams.

Herbs annual, biennial, or perennial. Leaf blade linear to ovate, rarely subulate. Inflorescences various, but often with vegetative branches arising within them. Sepals curved, often saccate, veins inconspicuous, margin broadly membranous, apex truncate. Petals usually longer than sepals (but sometimes smaller, cleistogamous flowers present), apex emarginate or shallowly bifid or toothed. Styles usually 2, rarely 3. Seeds often inflated, roughened, without reticulate striae.

McNeill (Notes Roy. Bot. Gard. Edinburgh 24: 129. 1962) mentioned that Arenaria subgen. Odontostemma is heterogeneous, but did not further subdivide it. The following five groups have been recognized in China: A. sect. Pseudoeuthalia C. Y. Wu (in W. T. Wang et al., Vasc. Pl. Hengduan Mount. 1: 396. 1993, but invalid as without Latin diagnosis; species nos. 44–51); A. sect. Reductae C. Y. Wu (loc. cit., but invalid as without Latin diagnosis; species nos. 52–64); A. sect. Moehringella Franchet (Pl. Delavay. 96. 1889; species nos. 65–74); A. sect. Macrogyne Franchet (Bull. Soc. Bot. France 33: 432. 1885; species nos. 75–79); and A. sect. Odontostemma (G. Don) Pax (in Engler & Prantl, Nat. Pflanzenfam. 3(1b): 84. 1889; species nos. 80–102).

About 65 species: Asia; 59 species (57 endemic) in China.