Herbs, annual, tufted, glabrous. Stems erect, simple or branched, not forming rosettes. Leaves alternate, spreading-erect, sessile; blade pea green, not glaucous, linear-oblong or oblong-elliptic, terete or subterete, ca. 6 × 2 mm, base not spurred, not scarious, apex obtuse, (surfaces papillose). Flowering shoots erect, simple, 3-15 cm; leaf blades linear-oblong or obovate-elliptic, base not spurred; offsets not formed. Inflorescences corymbiform cymes, 3-15-flowered, 2-3-branched; branches not recurved, not forked; bracts similar to leaves, smaller. Pedicels absent or to 1 mm. Flowers 5-merous; sepals spreading, distinct, green, lanceolate, unequal, 1.5-2.5 × 0.5-1 mm, apex acute; petals divergent in distal 1/2 from erect base, distinct, yellow, narrowly lanceolate, slightly carinate, 3-5 mm, apex acute; filaments yellowish or greenish; anthers yellow; nectar scales yellow, oblong. Carpels stellately spreading in fruit, distinct, light brown or yellow. 2n = 22.

Flowering summer. Sunny rocks, stony ground; 0-2000 m; introduced; Greenland; Europe.

Sedum annuum is similar to S. nuttallii; the latter has spurred sepals and smaller petals, nectaries, and follicles (R. T. Clausen 1975).