This biennial or annual is widely established across North America. In Ky. it has been common for a century or more, especially along roadsides and in rocky old fields. Though not generally cultivated, Gm noted: "I believe it is sometimes planted for bee pasture." M. albus is close to officinalis (and combined by K), but it differs (Isely 1998, W) in its white flowers (versus yellow), ca. 3.5-5 mm long (versus 5-7 mm), the wing petals about as long as the keel (versus generally longer). In Ky. albus mostly flowers later (Jun-Jul versus May-Jun) and tends to occurs on drier sites. Morever, there is evidence from phytochemistry (including cyanogenic glycosides) and DNA-sequencing that albus is a distinct (Rizk & Kamel 1991, Krzakowa & Grzywacz 2010, Di et al. 2015). The spelling "alba" is incorrect for the epithet (W).