Description

Key Characters:

Growth Form: Annual, biennial, or perennial herbs, occasionally subshrubs or shrubs, pubescent with simple hairs.

Stems:

Roots:

Leaves: Leaves simple. Alternate or rarely opposite. Margins entire, toothed, or 1–2 times pinnately divided, sometimes clasping the stem. Petiolate or sessile. Stipules absent.

Flowers: Flowers in usually bractless, terminal racemes, occasionally solitary. Flowers bisexual (perfect), actinomorphic or rarely slightly irregular; white, pale yellow, or greenish, usually 2–3 mm long, sometimes absent. Calyx of 4 sepals, deciduous, erect, usually oblong, sometimes the inner 2 with gibbous bases that hold the nectar. Corolla of 4 petals, rarely absent, yellow, white, or lavender, entire to emarginate, rarely lobed or fimbriate, usually with an elongate claw. Stamens 2, 4, or 6, 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 1 or occasionally absent; stigma capitate.

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; flattened at right angles to the septum; ovate or elliptic to orbicular or obovate; sometimes winged; apex often notched and tipped by the persistent style or stigma. [Drake del Castillo; 1890a; Fosberg; 1969; C. Hitchcock; 1945a; 1945b; Mann; 1867; Rollins; 1986; St. John; 1981c]. Seeds 1 to numerous; often becoming mucilaginous when wet; endosperm essentially absent.

Ploidy:

Habitat:

Elevation Range: