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Taxon  Report  
Epilobium rigidum  Hausskn.
Siskiyou mtns. willowherb,   Stiff willowherb
Epilobium rigidum is a perennial herb that is native to California, and also found in Oregon.
California Rare Plant Rank: 4.3 (limited distribution).
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial
Observation Search
~57 records in California
yellowone or more occurrences
within a 7.5-minute quadrangle
DJJJASONAFMM

Bloom Period
Genus: Epilobium
Family: Onagraceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Ultramafic affinity: 5.1 - broad endemic

Communities: Yellow Pine Forest

Name Status:
Accepted by JEF + CNPS + PLANTS + POWO
Alternate Names:
PLANTSEpilobium rigidum var. canescens
Information about  Epilobium rigidum from other sources
Nursery availability from CNPLX
Commercial availability unknown.
Jepson eFlora

USDA PLANTS Profile (EPRI)

Photos on Calflora

Photos on CalPhotos

Google Images

Photos on iNaturalist

ID Tips on PlantID.net

[Wikipedia] Limited Range, Habitat: It is endemic to the Klamath Mountains of far northern California and southern Oregon, where it grows in dry, open areas in lower elevation coniferous forest habitat, often on serpentine soils. (link added by Mary Ann Machi)


Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2025. The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 05/12/2025).