Island manroot Island manroot

Megarrhiza guadalupensis S. Watson, Proc. Amer. Acad. Arts 11: 115, 138. 1876; Marah macrocarpa (Greene) Greene var. major (Dunn) Stocking; M. major Dunn

Leaf blades deeply 5-lobed, (10–)15–20(–25) cm wide. Flowers: sepals (pistillate) linear, 6–7 mm; petals 8–10 mm (pistillate) or 6–7 mm (staminate), corolla white, shallowly cupulate; staminodia present in pistillate flowers. Capsules yellowish green at maturity, ovoid, beaked, 5–7 cm, surface sparsely hirsute-echinate, spinules weak, 1–3 mm. Seeds 2–4, orbiculate to elliptic or oblong, compressed, (22–)28–33 mm.

Flowering Feb–Apr. Washes, stream edges, grassy slopes, beach bluffs, roadsides; 0–200(–500) m; Calif.; Mexico (Baja California).

The nomenclatural type of Marah guadalupensis is from Guadalupe Island off the coast of Baja California; the main cluster of populations is on the Channel Islands of California (Santa Barbara County).