Marah watsonii
Taw man-root, Taw Man-Root
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Family: Cucurbitaceae · Type: Vine · Native
Marah watsonii (Taw man-root) is a native California vine in the Cucurbitaceae family, recognized by glaucous herbage, small fruit, and small corolla.
Taw man-root is a California native perennial found in the Klamath Ranges, northern Coast Ranges, southern Cascade Range, northern Sierra Nevada, and Sacramento Valley in shrubby areas and forest edges at elevations below 1,200 meters. Flowering from March to April, this plant produces small white flowers in deeply cup-shaped corollas less than 8 millimeters wide. Growing with glaucous herbage and flexible stems, it develops a distinctive vine-like habit across shrubby landscapes. Its leaves spread broadly across the ground, with a pale bluish-green cast that helps it blend into woodland and chaparral environments. The fruit is nearly spherical, often striped in dark green and measuring 2 to 3.5 centimeters, typically bearing flexible prickles that can be sparse or dense.
Identification and appearance
Key characters: 3 sympatric species; key features are glaucous herbage, small fruit, and small corolla
Habitat and range
Habitat: shrubby areas, forest edges
Elevation: < 1200 m
California counties: Colusa, Amador, Butte, Calaveras, Placer, Solano, Yolo, Napa, El Dorado, Nevada, Shasta, Tuolumne, Mendocino, Yuba, Lake, Glenn, Mariposa
Bloom period
Marah watsonii 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 watsonii native to California?
Yes. Marah watsonii is native to California (recorded as native).
When does Marah watsonii bloom?
Marah watsonii blooms Mar-Apr.
Where in California does Marah watsonii grow?
Marah watsonii occurs in Colusa, Amador, Butte, Calaveras, Placer, Solano, Yolo, Napa and other counties, at elevations of < 1200 m.
What plant family does Marah watsonii belong to?
Marah watsonii is in the Cucurbitaceae family, genus Marah.
What habitat does Marah watsonii grow in?
Marah watsonii grows in shrubby areas, forest edges.
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.