Cardamine micranthera Rollins. Phen: Apr-May; May-Jun. Hab: Sand and gravel bars in creeks, swampy floodplain woods, seepage over rocks. Dist: A narrow endemic, known only from Stokes County, NC and Patrick County, VA, and apparently extirpated from Forsyth County, NC
Origin/Endemic status: Endemic
Other Comments: The description and key in RAB are partly in error, being based on the inadequate and unrepresentative material available at the time. C. micranthera is most closely related to C. rotundifolia, but also shows some affinities to C. pensylvanica. It can be distinguished from C. rotundifolia by the characters in the key; additionally, C. micranthera does not form proliferative branches from the upper nodes, generally branching from the base in vigorous plants, or unbranched in smaller plants. It can be distinguished from C. pensylvanica by its predominately simple leaves, especially those on the upper stem, the larger flowers, the petals 3-5 mm long (vs. 1.5-3 mm long), the fruiting pedicels thin, 10-20 mm long, spreading to ascending (vs. thick, 4-10 mm long, ascending). Wieboldt (1992) reasonably speculates that C. micranthera may be an in-breeding relative derived from C. rotundifolia in the Piedmont/Mountain interface.
Synonymy: = FNA7, K1, K3, K4, RAB, Va, Al-Shehbaz (1988a), Rollins (1993); = n/a – C, F