7. Marah horrida (Congdon) Dunn, Bull. Misc. Inform. Kew. 1913: 151. 1913. (as horridus).
Sierran manroot Sierran manroot
Echinocystis horrida Congdon, Erythea 7: 184. 1900
Leaf blades deeply 5–7-lobed, 10–15 cm wide. Flowers: sepals (pistillate) filiform, 1 mm; petals 7–9 mm (pistillate) or 5–7 mm (staminate), corolla white, deeply cupulate to campanulate or campanulate-rotate; staminodia present in pistillate flowers. Capsules yellowish green to orange-yellow at maturity, short-ellipsoid to oblong, 9–15(–20) cm, surface densely echinate, spinules rigid, 5–35 mm. Seeds 6–16(–24), oblong to oblanceolate or ovate, flat at one end, slightly compressed, 26–32 mm.
Flowering Feb–Apr(–May). Canyons, open ridges, shrubby and open areas, pine, oak, and pine-oak woodlands, stream sides, roadsides; 300–1200(–1600) m; Calif.
Marah horrida is distributed from Los Angeles County to El Dorado County in the California Sierra Madre.