Lotus L. (trefoil)

About 125 species, Europe, Asia, Africa, introduced nearly worldwide.

Most botanists have treated the genus Lotus in a broad sense, with various numbers of infrageneric groups differing in stipule, flower, fruit, and pollen morphologies (Ottley, 1944; Callen, 1959; Isely, 1981). More recently, evidence has begun to accumulate that the Old World species of Lotus (including the type species, L. corniculatus) are distinct from those in the New World. The species included by Steyermark (1963) and other authors as Lotus purshianus is treated in the segregate genus Acmispon in the present work. For further discussion of that species, see the treatment of Acmispon.

Lotus corniculatus is economically important in many countries as a forage and cover crop, and other species also are planted for erosion control.