Taproots gradually ramified distally. Stems procumbent, 3-6 cm. Leaves: basal leaves withering at or soon after anthesis, gradually narrowed to broad petiole, blade narrowly linear to linear-oblanceolate, flattened or channeled adaxially, 2.5-6 cm, margins entire, apex acute; cauline leaves absent. Inflorescences usually with flowers borne singly, sometimes 2-3-flowered racemose cymes; bracts 2, opposite, plus 1 subtending each successive flower if 2 or more flowers present, lanceolate, 5 mm, margins glandular-toothed, apex acute. Flowers pedicellate, not disarticulate in fruit, 2.5-4 cm diam.; sepals 2, broadly obovate, 4-10 mm, herbaceous at anthesis, margins glandular-toothed, apex rounded to truncate; petals 5-10, white to very pale pink, often with reddish glands at apex, narrowly elliptic-oblong, 11-20 mm; stamens 7-9; stigmas 5-6; pedicel 10-25 mm. Capsules 8 mm. Seeds 20-50, 1.5 mm, dullish, minutely granular. 2n = ca. 22.
Flowering mid-late summer. Rock crevices or damp scree near melting snow; of conservation concern; 2600 m; Calif.
Lewisia longipetala is known only from the northern Sierra Nevada in Eldorado and Placer counties.