Clypeola maritima Linnaeus, Sp. Pl. 2: 652. 1753; Alyssum halimifolium Linnaeus; A. maritimum (Linnaeus) Lamarck; A. minimum Linnaeus; Koniga maritima (Linnaeus) R. Brown.

Herbs perennial, sometimes suffruticose, (5-)12-24(-40) cm tall, silvery pubescent. Stems erect, ascending, procumbent, or decumbent, basally branched; pubescent. Leaves linear, lanceolate, or oblanceolate, (1-)1.5-2.5(-4) cm × (0.8-)1.5-3(-6.5) mm, pubescent, base attenuate, margin entire, apex acute to subobtuse. Racemes many flowered, elongated considerably in fruit. Fruiting pedicels divaricate or ascending, straight, slender, (3-)5-7(-10) mm, pubescent. Sepals green or purple, oblong, 1.5-1.8(-2.4) × 0.5-1 mm, pubescent. Petals white or deep purple, obovate or suborbicular, 2-3 × 1.5-2.5(-3) mm, abruptly narrowed to claw; claw to 1 mm. Filaments white or purple, 1.2-2 mm; anthers ovate, 0.3-0.5 mm. Fruit ovate, elliptic, or orbicular, (2-)2.3-3(-4.2) × (1.2-)1.5-2(-3) mm; valves convex, pubescent, with a distinct midvein; style 0.4-0.6 mm. Seeds light to reddish brown, 1 per ovary, lenticular, ovate or suborbicular, (1-)1.2-1.4(-2) × (0.7-)0.9-1.1(-1.5), wingless or with a narrow wing to 0.1 mm wide. Fl. and fr. throughout the year depending on locality. 2n = 24.

Stony areas, waste grounds, yards; sea level to 2000 m. Cultivated in most of China, naturalized in Gansu, Hebei, Jiangsu, Shaanxi, Shandong, Shanxi, Taiwan, Xinjiang, Zhejiang [native to W Mediterranean region; naturalized elsewhere].