Description

Key Characters:

Growth Form: Annual or biennial herbs, glabrous to sparsely hirsute with simple hairs.

Stems: Stems flexuous, ascending to weakly erect, 1–3 dm long, ± sparsely hirsute to subglabrate.

Roots: Sometimes rhizomatous or stoloniferous.

Leaves: Leaves compound (odd-pinnate). Alternate, basal and usually cauline. Blades oddly–pinnately compound with 3–11 leaflets, basal leaves usually with more leaflets than cauline leaves, the leaflets ovate to reniform, rarely lanceolate, blades of lateral leaflets 2–10 mm long, 1.5–15 mm wide, 3–5–lobed, the terminal leaflet usually larger, 5–15(–25) mm long, 6–17 mm wide, usually lobed similar to lateral leaflets. Apex apiculate. Surfaces sparsely hirsute to subglabrous; blades thin. Leaflet margins repand, crenate, or 3 or 5-lobed. Veins evident. Petiolate. Stipules absent.

Flowers: Flowers in 1 to several racemes 10–20 cm long. Flowers bisexual (perfect), actinomorphic or rarely slightly irregular. Calyx of 4 sepals, deciduous, erect, usually oblong, sometimes the inner 2 with gibbous bases that hold the nectar. Corolla of 4 petals, white, 2.5–3 mm long, not exceeding the sepals. Stamens usually 6, usually divaricately ascending. Ovary superior, 2(4?)-carpellate, usually 2-celled by means of a false, but usually complete septum, rarely 1-celled, sessile or rarely stipitate; ovules 1 to numerous, borne on parietal placentas on replum margin at periphery of ovary wall, campylotropous or occasionally anatropous; style 1 or occasionally absent; stigma capitate or rarely decurrent, entire or 2-lobed.

Fruit: Linear silique; erect; slightly compressed parallel to the septum; the valves opening elastically from base; rolling up after dehiscence; the septum margin extending partially over the valvular area; siliques (1–)1.4–2(–2.5) cm long. Seeds in a single series per cell; plump; longer than wide; wingless; 8–14 per cell; reddish brown; broadly oblong; 0.9–1.1 mm long.

Ploidy: 2n = 30; 32

Habitat: Naturalized in wet to seasonally wet sites in low elevation; disturbed areas to open or shaded areas at higher elevations in wet forest; especially in gulches or streambeds.

Elevation Range: