Perennials, underground stems ± woody. Herbage hairy, hairs appressed or spreading, whitish. Stems trailing or twining-climbing, to 100 cm. Leaves: blade palmately 7–9-lobed, lobes linear to linear-oblong, to 55 × 6 mm, base ± truncate. Bracts to 18 mm distant from sepals, margins palmately 3–7(–9)-lobed, lobes to 18 × 3 mm. Flowers: sepals 7–11 mm, basally glabrous or hairy; corolla cream, yellow, or pink-striped, 30–35 mm.

Flowering Apr–Jul. Chaparral, foothills; of con­servation concern; 300–700 m; Calif.

Calystegia stebbinsii is notable for having no intermediates or hybrids with any other species or any significant infraspecific variants. In some characters, it is similar to C. vanzuukiae; they grow in similar habitats.