About Rorippa sessiliflora (Nutt.) Hitchc.
Rorippa sessiliflora (Nutt.) Hitchc. is a glabrous (hairless) annual plant with erect stems. Its species epithet "sessiliflora" refers to its short pedicels, which measure 0.5–2 mm in length. Compared to other species in the genus Rorippa, Stuckey identified additional distinctive characteristics for this species, including thick siliques that are wedge-shaped at the base. While some sources state that this plant lacks petals, Radford et al. report that it has tiny petals less than 1.5 mm long. Stuckey notes that Rorippa sessiliflora flowers can deviate from standard crucifer traits: individual plants can have variable stamen counts ranging from 3 to 6, and anther fusion occasionally occurs. Rorippa sessiliflora is native to midwestern and eastern United States. Its native range extends from South Dakota south to Texas, and east from Maryland south through Florida. This species occurs more frequently in the midwest than in the southeast. The northern limit of its native distribution matches the southern edge of the Wisconsin glaciation. Occasional collections of the species from previously glaciated areas further north, as well as from Massachusetts, are likely the result of human-caused dispersal. This species grows in muddy, disturbed sites. These include the banks of streams, ponds, and lakes, as well as roadsides and fallow fields.
