Annuals or, rarely, perennials; (succulent, taproot woody, with relatively long, horizontal roots); not scapose; glabrous or, sometimes, sparsely pubescent. Stems erect, ascending, prostrate, or divaricate, branched basally. Leaves cauline; usually petiolate, rarely sessile; blade (often fleshy), not rosulate, margins entire, crenate, dentate, sinuate, or pinnately lobed. Racemes considerably elongated in fruit. Fruiting pedicels (rachis) geniculate or not, slender or stout. Flowers: sepals erect, ovate or oblong, lateral pair saccate or not basally; petals (rarely aborted, reflexed), white to lavender, obovate to spatulate, claw differentiated from blade or not; stamens tetradynamous; filaments not dilated basally; anthers (introrse), ovate to oblong; nectar glands (4), distinct, median glands present. Fruits siliques or silicles, indehiscent, stipitate, segments 2, (fleshy and green becoming corky and dry), obovoid, oblong, fusiform, or lanceoloid, rarely hastate, (proximal segment) terete or laterally horned, (terminal segment) terete, 4-angled, or 8-ribbed; (segments each falsely 1-loculed, septum papery, appressed to one side, usually 1-seeded; proximal segment remaining attached to pedicel; terminal segment deciduous by transverse articulation, beaked); valves and replum not distinguishable; ovules (1 or) 2(-4) per ovary; (style absent); stigma entire or slightly 2-lobed. Seeds aseriate or uniseriate, plump or flattened, not winged, (brown), oblong; seed coat (smooth), not mucilaginous when wetted; cotyledons accumbent or incumbent, rarely contorted. x = 9.
Pet obovate, pink or purplish to white; short stamens subtended by a minute gland, long stamens separated by a larger gland; anthers ovate-oblong; ovary cylindric, with imperfect septum; ovules 2-4; style not differentiated; stigma truncate; fr indehiscent, corky when dry, transversely divided into 2 dissimilar joints, the lower persistent, 1-seeded or seedless, the upper eventually deciduous, fertile, usually 1-seeded, ovoid or lance-ovoid, 2- or 4-angled or ±8-angled (2 sutures, and 3 nerves for each valve); seed suspended in the lower joint, erect in the upper; coarse, succulent annuals of coastal sands, much-branched, with spreading or ascending stems and oblanceolate to obovate, dentate to pinnatifid lvs. 7, widespread.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.