Spring Cress (Bitter Cress)
Low, spreading perennial. Flowers small, 4-petaled, white, terminal, in small clusters. Blooms March–June. When rooted in water, the stem leaves are narrowly lance-shaped; when rooted in wet earth, stem leaves are triangular with some teeth, the lower on long petioles, the upper to nearly sessile. Basal leaves are rounded on long stems.
Similar species: Small-flowered bitter cress (C. parviflora) has mostly single stems with little or no branching, to 12 inches tall. Blooms March-July. Basal and stem leaves with 3-6 pairs of small, opposite lobes spaced along the leaf rib, the terminal having the same nearly linear shape. Statewide, in upland, rocky woods and ridges.
Bitter cress (C. pensylvanica) has stems single or spreading, to 2 feet tall. Blooms March-July. Leaves like C. parviflora, but larger, and the lobes are connected by leaf tissue along the midrib of the leaf. Moist places in central and southern counties.