Herbs, perennial, mat-forming, glabrous. Stems procumbent, becoming erect, (reddish-shiny proximally), long-branched, not bearing rosettes. Leaves alternate, (densely set), erect to slightly spreading, sessile; blade green with prominent red dots, not glaucous, sometimes waxy, orbiculate to broadly obovate, semiterete, 2.5-3.5(-5) × 2-2.5 mm, base not spurred, not scarious, apex rounded to acute. Flowering shoots erect, simple or branched, 2-4 cm; leaf blades orbiculate to broadly ovate, base not spurred; offsets not formed. Inflorescences subscorpioid cymes, 10-20-flowered, simple to 2-branched; branches erect to spreading or recurved, sometimes forked; bracts oblong, ca. 3 mm, base broadly spurred. Pedicels absent. Flowers 5-merous; sepals suberect, distinct basally, greenish, sometimes with reddish striations, subovate, unequal, 2-2.5 × 0.1-1.6 mm, apex obtuse, (papillose); petals erect to spreading, distinct, yellow with prominent, short, longitudinal red stripes, lanceolate, carinate, 4.5-5 mm, apex subobtuse, narrowly mucronate; filaments whitish or pale yellow; anthers yellow; nectar scales inconspicuous. Carpels spreading in fruit, distinct, tan or brown with reddish striations. 2n = 52, 53, 104.

Flowering late spring-early winter. Limestone gravel or outcrops in various vegetation; 1300-2000 m; Tex.; Mexico (Chihuahua, Coahuila, Nuevo León).

Sedum nanifolium is found in the Del Norte Mountains of Brewster County. The long-branched (to 20 cm), reddish-shiny stems are distinctive; see discussion under 19. S. robertsianum.