Marah horrida
Sierra man-root
(c) Ken-ichi Ueda, some rights reserved (CC BY) · licence
Family: Cucurbitaceae · Type: Vine · Native
Marah horrida (Sierra man-root) is a native California vine in the Cucurbitaceae family, recognized by large oblong fruit with dense prickles and many seeds.
Sierra man-root is a California native perennial found in central Sierra Nevada Foothills and Tehama County in shrubby open areas at elevations below 1,000 meters. Flowering from March to April, this plant produces white flowers more than 8 millimeters wide, deeply cup-shaped and conspicuous. Growing with sprawling vines that can extend several meters, it develops a robust, prickly stems and tendrils. Its leaves are variable, with rough textured surfaces supporting the plant's distinctive "horrida" name, suggesting its spiny, tangled growth habit. The fruit is particularly notable, developing into large oblong structures 9 to 20 centimeters long, densely covered with stiff, unhooked prickles and containing 6 to 16 large seeds.
Identification and appearance
Key characters: 2 sympatric species; key features are large oblong fruit with dense prickles and many seeds
Habitat and range
Habitat: shrubby open areas
Elevation: < 1000 m
Bloom period
Marah horrida blooms Mar-Apr.
How to tell it apart
vs Echinocystis: Marah fruits are beaked and symmetric; Echinocystis fruits lack prominent beaks.; vs Delairea: Marah is a cucurbit vine with tendrils; Delairea is a composite with daisy-like flowers.; vs Brandegea: Marah flowers are 3 mm or larger; Brandegea flowers are under 3 mm.; vs Vitis: Marah has white flowers and spiny fruits; Vitis has grapes and opposite leaves with tendrils.; vs Cucumis: Marah flowers are white/cream; Cucumis flowers are yellow.
Frequently asked questions
Is Marah horrida native to California?
Yes. Marah horrida is native to California (recorded as native).
When does Marah horrida bloom?
Marah horrida blooms Mar-Apr.
What plant family does Marah horrida belong to?
Marah horrida is in the Cucurbitaceae family, genus Marah.
What habitat does Marah horrida grow in?
Marah horrida grows in shrubby open areas.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.