ODONTARRHENA C.A.Mey. ex Ledeb., Icon. Pl. Nov. 2 : 15 (1830).

Herbs perennial with woody, usually branched caudex, some branches terminated with sterile shoots and rosettes, rarely shrubs. Trichomes sessile, (6–)8–20(–24)-rayed, stellate without webbing between the rays, appressed, with rigid or soft rays. Multicellular glands absent. Stems erect to ascending, sometimes decumbent, simple or branched basally and/or apically, leafy, not spiny. Basal leaves petiolate, rosulate or not, simple, entire; cauline leaves petiolate or subsessile, cuneate to attenuate, not auriculate at base, entire. Racemes several to many flowered, ebracteate, corymbose, elongated slightly or considerably in fruit; rachis straight; fruiting pedicels divaricate, sigmoid, or deflexed, rigid or filiform, persistent. Sepals ovate to oblong, free, deciduous, erect to ascending, equal, base of lateral pair not saccate; petals yellow, erect at base with flaring blade, longer than sepals; blade obovate to oblanceolate, apex obtuse or retuse; claw slightly or strongly differentiated from blade, longer shorter than sepals, glabrous, rarely with a basal appendage, entire; stamens 6, 4, little exserted, erect, slightly tetradynamous; filaments with free or united, entire or toothed winged appendages, free, glabrous; anthers ovate or rarely oblong, not apiculate; nectar glands 4, lateral, 1on each of lateral stamen, median glands absent; ovules 2 per ovary; placentation subapical. Fruit dehiscent capsular silicles, rarely indehiscent and samaroid, ovate, obovate, oblong, elliptic, or suborbicular, rarely globose, strongly latiseptate or rarely terete, not or unilaterally inflated, rarely inflated, unsegmented; valves papery, veinless, glabrous or appressed pubescent, rarely papillate-puberulent, not or rarely keeled, smooth, wingless rarely narrowly winged, unappendaged; gynophore absent or obsolete; replum rounded visible or connate with valve margins; septum complete, membranous, veinless; style 1–3 mm long, filiform, persistent; stigma capitate, entire, unappendaged. Seeds aseriate, winged or wingless, ovate, flattened; seed coat not or rarely mucilaginous when wetted; cotyledons accumbent.