7. Soleirolia Gaudichaud Beaupré, Voy. Uranie, Bot. 12: 503. 1830.
[For Captain Soleirol, collector in Corsica]
Herbs , perennial, with nonstinging hairs. Stems 1-25-branched, repent, filiform, mat-forming. Leaves alternate; stipules absent. Leaf blades orbiculate to oblong, margins entire; cystoliths elongate, linear. Inflorescences axillary, 1-flowered. Flowers unisexual, proximal flowers pistillate, the distal staminate; bracts subtending pistillate flowers developing 3 corky wings covered with fine, hooked hairs in fruit. Staminate flowers: tepals 4, distinct, equal; stamens4; pistillode obovate. Pistillate flowers: tepals 4, connate, lacking hooked hairs; staminodes absent; stigma filiform, deciduous. Achenes sessile, ovoid, apex acute, tightly enclosed by scarious perianth and surrounded by connivent, winged bracteoles. x =10.
Species 1: North America; Europe (Sardinia and Corsica).
This monotypic genus was first reported naturalized in California in 1940.
Robbins, W.W. 1940. Alien plants growing without cultivation in California. Univ. Calif. Agric. Exp. Sta. Bull. 637: 1-128.