About Cardamine douglassii Britton
Cardamine douglassii Britton produces an erect, unbranched stem that grows 10 to 25 centimeters (4 to 10 inches) tall, with sparse to dense hair coverage. Its basal leaves are simple, heart-shaped or round, measuring 5 to 15 cm (2 to 6 in) across, and grow on petioles 4 to 12 cm (1+1⁄2 to 4+3⁄4 in) long. The stem bears 3 to 8 oblong to lanceolate leaves, each 2 to 5 cm (3⁄4 to 2 in) long and 5 to 25 millimeters (1⁄4 to 1 in) wide. Leaf margins can be either smooth or coarsely toothed. Petal color ranges from purple to purplish white, and fully white petals are rare for this species. The flowers grow in a raceme inflorescence and typically bloom from mid-March to late April. Individual petals measure 7 to 15 mm (1⁄4 to 1⁄2 in) long and 3 to 5 mm wide. The fruit is linear, 1.5 to 4 cm (1⁄2 to 1+1⁄2 in) long and 1.5 to 2 mm wide. This species is widely distributed across Ontario, as well as eastern and central United States, though local populations may be scattered. Its range extends from Massachusetts west to Ontario, Minnesota, and Missouri, and south to Arkansas, Alabama, and the Carolinas. It is listed as an endangered species in Massachusetts, and a species of special concern in Connecticut. In Virginia, it grows in swamps and forest habitats, generally in base-rich soils. Its survival relies on the presence of suitable habitat, and it can be eliminated from an area by development, changes in land use, or competition with invasive species.
