Small-Anthered Bittercress (Cardamine micranthera)
Family: Mustard (Brassicaceae)
Federal Status: Endangered, listed September 21, 1989
Best Search Time: April through May
Description: Small-anthered bittercress is an erect, slender perennial herb with fibrous roots and one (or rarely more) simple or branched stem growing 7.9 – 15.8 inches (in) 2 - 4 decimeters tall. Basal leaves are 0.4 – 2 in (1 – 5 centimeters; cm) long, and 0.2 – 0.8 in (0.5 - 2 cm) wide. The stem leaves are alternate and mostly unlobed, 0.4 – 0.6 in (1 - 1.5 cm) long. Flowering and fruiting occur in April and May. The flowers, surrounded by leafy bracts, have four white petals, six stamens, and small, round anthers.
Habitat: Small-anthered bittercress is found in seepages, wet rock crevices, stream banks, sandbars, and wet woods along small streams, in fully to partially-shaded areas.
Distribution: Small-anthered bittercress is known only from the Dan River basin in north-central North Carolina (Stokes County) and south-central Virginia (Patrick County).
Threats: With a very limited range, and found in close association with water, the plant is threatened by stream impoundments, channelization, water contamination, as well increased stormwater runoff which can abnormally increase the volume and velocity of stream flows, eroding stream banks and beds. Encroachment of invasive exotic plant species, like Japanese honeysuckle, is also a threat. Many remaining sites are adjacent to agricultural fields and pastures. Accidental herbicide drift or run off could be detrimental, as could trampling and erosion on sites where livestock are allowed free access.
References:Buchanan, M.F. and J.T. Finnegan. 2010. Natural Heritage Program List of the Rare Plant Species of North Carolina. N.C. Natural Heritage Program, Raleigh, NC.
U.S. Fish and Wildlife Service. 1991. Small-anthered Bittercress Recovery Plan. Atlanta, GA. 22 pp.
For More Information on Small-Anthered Bittercress...
- U.S. Fish and Wildlife Service Environmental Conservation Online System
- Small-Anthered Bittercress Recovery Plan
- U.S. Department of Agriculture Natural Resource Conservation Service Plants Database
- Center for Plant Conservation species profile
Mara Alexander, Fish and Wildlife Biologist, 828-258-3939 ext. 238
Species profile revised on September 15, 2011.