Description

Key Characters:

Growth Form: Annual herbs, subglabrous to sparsely pubescent, but not glandular pubescent.

Stems: Stems 2–8 dm long, single from the base, branched above.

Roots:

Leaves: Leaves simple. Alternate or rarely opposite, basal leaves usually quickly deciduous. Basal leaves 2–3 times pinnately compound. cauline leaves similar, the segments usually linear, sometimes elliptic to obovate. Margins of basal leaves sometimes toothed. Petiolate. Stipules absent.

Flowers: Flowers in elongated, loose racemes. Flowers bisexual (perfect), actinomorphic or rarely slightly irregular. Calyx of 4 sepals, deciduous, erect, narrowly elliptic to linear, sometimes the inner 2 with gibbous bases that hold the nectar. Corolla of 4 petals, yellowish green, less than 3 mm long, entire to emarginate, rarely lobed or fibriate, usually with an elongate claw. Stamens (2–4)6(–16), tetradynamous, the inner 4 usually in pairs, sometimes connate at base in pairs; anthers dithecal, opening by longitudinal slits. 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 short or absent; stigma capitate or rarely decurrent, entire or 2-lobed.

Fruit: Capsules divided into 2 cells by the usually thin and membranous septum; elongate (at least 3 times as long as wide) and referred to as a silique; siliques terete (cylindrical); usually torulose and curved; occasionally straight; 1–3 cm long; fruit dehiscent. Seeds in 1 row per cell; oblong–ellipsoid; 0.8–1.5 mm long; often becoming mucilaginous when wet; endosperm essentially absent.

Ploidy: 2n = 14; 20; 28.

Habitat:

Elevation Range: