1. Aubrieta deltoidea (L.) DC. (purple alyssum, aubrietia)

Pl. 314 f, g; Map 1316

Plants perennial herbs, terrestrial. Stems (5–)10–30 cm long, spreading or creeping, usually somewhat branched from the base, sometimes forming clumps or mats, sparsely to densely pubescent with unbranched and stalked, branched, and/or stellate hairs. Leaves alternate, (0.5–)1.0–3.0 cm long, sessile, the bases not clasping, broadly spatulate, oblanceolate, to narrowly obovate, the margins entire or coarsely few-toothed, sparsely to densely pubescent with branched and stellate hairs mixed on the lower surface with much fewer unbranched hairs. Inflorescences racemes or few-branched panicles, the lower branches subtended by reduced leaves. Sepals 6–10 mm long, ascending, oblong, hairy. Petals 12–28 mm long, unlobed, reddish purple. Styles 4–8 mm long. Fruits spreading to ascending, 6–18 mm long, 2–5 times as long as wide, narrowly oblong to elliptic, somewhat flattened parallel to the septum, hairy, dehiscing longitudinally, each valve with a midnerve. Seeds in 2 rows in each locule, 1.2–1.5 mm long, ovoid, the surface roughened, black. 2n=16. April–June.

Introduced, known only from Boone County (native of Europe, rarely escaped in the U.S.). Disturbed ground.

Aubrieta deltoidea is commonly cultivated in flower beds and rock gardens, and various hybrids and cultivars exist. It is unknown whether plants have become naturalized at the single locality reported by Dunn (1982), and this species perhaps should not be regarded as a member of the flora.