28 Records

A very rare plant of fresh tidal marshes. Endangered by habitat loss, stream sedimentation and to an unknown extent, sea level rise associated with global warming (MD DNR). The Wicomico County population is extirpated. Sensitive Jointvetch is a regional endemic. Historically it was found in Pennsylvania and Delaware but is now extirpated from those states. Populations are now known from New Jersey, Maryland, Virginia, and North Carolina. Sensitive Jointvetch was listed as federally threatened in May of 1992.

Sensitive joint-vetch typically grows in the intertidal zone of coastal marshes where plants are flooded twice daily. The species seems to prefer the marsh edge at an elevation near the upper limit of tidal fluctuation. It is usually found in areas where plant diversity is high (50 species per acre) and annual species predominate. Bare to sparsely vegetated substrates appear to be a habitat feature of critical importance to this plant. As an annual, it requires such microhabitats for establishment and growth. Such areas may include accreting point bars that have not yet been colonized by perennial species, low swales within extensive marshes, or areas where muskrats have eaten most of the vegetation. It appears to remain at a particular site for a relatively short period of time, and maintains itself by colonizing new, recently disturbed habitats where it may compete successfully among other early-successional species (US Fish and Wildlife Service).