Rio Grande wild buckwheat

Eriogonum riograndis G. L. Nesom, Sida 20: 32, fig. 1. 2003

Leaf blades oblong to narrowly ovate, 1.5-4(-4.5) × 1-2.2(-2.5) cm, floccose to glabrate adaxially, occasionally thickened, auri-culate-subclasping proximally.

Flowering Aug-Nov. Sandy to gravelly flats and slopes, mixed grassland and mesquite communities, oak and conifer woodlands; 0-300 m; Tex.

Variety riograndis is mostly infrequent and widely scattered in central southern Texas (Aransas, Brooks, Calhoun, Cameron, Duval, Hidalgo, Jim Hogg, Jim Wells, Karnes, Kenedy, Kleberg, Nueces, Refugio, San Patricio, Webb, Willacy, Wilson, and Zapata counties), becoming common only near the coast.

Variety riograndis is found just to the west and south of var. multiflorum, and a series of overlapping (and intergrading) populations occurs along their shared boundary. Plants immediately along the coast of Texas often have thickened, almost crassulate leaf blades.