ALYSSOIDES Mill., Gard. Dict. Abr., ed. 4 (1754).

Herbs perennials with many-branched woody caudex. Trichomes sessile, appressed, 3–7-rayed stellate mixed with malpighiaceous ones, plus simple ones on petiole. Multicellular glands absent. Stems erect, simple, densely leafy, glabrous above, not spiny. Basal leaves with long-ciliate petiole, rosulate, simple, sparsely pubescent with trichomes the rays parallel to midvein longest; cauline leaves numerous, subsessile, not auriculate at base, entire, glabrous. Racemes many flowered, corymbose, ebracteate, elongated considerably in fruit; rachis straight; fruiting arcuate-divaricate, articulate at base, persistent. Sepals narrowly oblong to linear, free, deciduous, erect, sparsely pubescent with few-rayed trichomes with 2 longer rays parallel to sepals long axis, unequal, base of lateral pair strongly saccate; petals golden yellow, erect at base with flaring blade, longer than sepals; blade obovate, to spatulate, apex rounded; claw strongly differentiated from blade, slightly longer than sepals, glabrous, unappendaged, entire; stamens 6, slightly exserted, erect, strongly tetradynamous; median filaments narrowly winged, unappendaged, glabrous, free; anthers oblong, not apiculate; nectar glands 2, lateral, ring-like or U-shaped and subtending lateral stamens, sometimes 2 and 1 on each side of lateral stamens, median glands absent; ovules 8–12 per ovary; placentation parietal. Fruit dehiscent, capsular silicles, globose to globose-ovoid, terete, inflated, unsegmented; valves thickened, leathery to subwoody, veinless, glabrous outside and inside, not keeled, smooth, wingless, unappendaged; gynophore obsolete or to 0.5 mm; replum rounded flattened, concealed by thickened valve margins; septum complete, membranous, veinless; style 6–10 mm long, filiform, glabrous, often caducous; stigma capitate, slightly 2-lobed, lobes free, not decurrent, opposite replum, unappendaged. Seeds biseriate, broadly winged all around, orbicular, strongly flattened; seed coat minutely reticulate, not mucilaginous when wetted; cotyledons accumbent.