Cardamine micranthera is a member of the mustard family, a perennial herb with fibrous roots and one simple, sometimes branched, stem growing two to four decimeters tall. Small-anthered bittercress is distinguished by its basal leaves and white, four petaled, flowers which are evident in April and May. Little is known of the life history of this species, including the identity of its pollinators, reproduction requirements and seed viability rates. Investigations of the plant’s biology remained needed for habitat management guidelines to be established.

The total global distribution of Small-anthered bittercress is confined to the Dan River system in Stokes County, North Carolina, and Patrick County, Virginia. Recent monitoring data shows that two of the 37 known populations have increased in size over a 20-year period.  The majority of the known populations are decreasing in size and five are now extirpated. 

Habitat

Cardamine micaranthera occupies habitats along the Dan River system.

Physical characteristics

Cardamine micranthera is an erect slender perennial haerb with fibrous roots and one, rarely more, simple or branched stems growing 2 to 4 decimeters tall. Basal leaves are 1 to 5 centimeters long, 0.5 to 2.0 centimeters wide, crenate, with one, rarely two, pairs of small lateral lobes or leaflets. The stem leaves are alternate and mostly unlobed, 1 to 1.5 centimeters long, crenate and cuneate. Flowering and fruiting occur in April and May.  The flowers, subtended by leafy bracts, have four white petals, six stamens, and small, round anthers. The fruit is a silique, 0.8 to 1.2 centimeters longa nd approximately 1 millimeter in diameter, with a beak 1 to 1.2 millimeters long. The brown seeds are approximately 1 millimeter long. 

Reproduction

Very little is known of the life history of this species, including the identity of its pollinators; however, ants have been observed visiting the flowers.