Herbs, perennial, cespitose, glabrous. Stems rootstocks, erect, branched from base, bearing rosettes. Leaves alternate, erect, sessile; blade green, appearing whitish because of pruinose covering, margins green, not white, strongly pruinose, not glaucous, narrowly obovate, laminar, 7-38 × 5-9 mm, base spurred, not scarious, apex usually obtuse to truncate, sometimes emarginate. Flowering shoots erect, simple, 6-15 cm; leaf blades oblanceolate-oblong, base short-spurred; offsets not formed. Inflorescences dense, paniculate cymes, 30-60-flowered, 7-9-branched; branches not recurved, somewhat forked; bracts similar to leaves, smaller. Pedicels 3-5 mm. Flowers 5-merous; sepals erect, connate basally, green, appearing blue-green, glaucous, lanceolate-oblong, equal, 4-7 × 1.5-3.2 mm, apex acute, (papillose); petals erect, connate basally, creamy white, oblong, not carinate, 8.5-11.5 mm, apex acute, mucronate; filaments white, becoming reddish; anthers yellow; nectar scales yellow, transversely oblong. Carpels erect in fruit, connate basally, brown. 2n = 30.

Flowering summer. Rocky slopes, in crevices, edges of rocks; 400-1600 m; Calif., Oreg.

Sedum oblanceolatum is restricted to the upper Klamath and Applegate river basins in Jackson County, Oregon, and Siskiyou County, California. Represented by relatively few individual plants, it occurs on a wide range of substrates including phyllite-schist, schist, metavolcanics, metasedimentary, as well as ultramafics like serpentine, soapstone, and peridotite. It is of conservation concern in California.