Strophostyles leiosperma, known as slickseed fuzzybean, or smoothseed / small-flower wildbean[1] [2] is a species of herbaceous, vining legume native to the central to western U.S. It occurs west to Colorado and New Mexico, east to Louisiana, south to Mexico, and north to Minnesota.[3] [4] It is most easily distinguished from the other two Strophostyles species by the abundance of small silky hairs on its leaves and pods, and small pea-shaped flowers with a much reduced keel that is largely hidden by the wing petals.
This species is an annual to short-lived perennial. All parts tend to be smaller for S. leiosperma in general than its congeners, and it is a more diminutive plant overall. The leaflets are typically thin and rarely lobed (never deeply lobed). Unlike its congeners, its seeds rarely have a waxy, hairy covering, and it tends to occur in drier sites. Likewise, the specific epithet leiosperma means "smooth seed."[5] It is also the most likely of these species to be capable of self-fertilization.