Epilobium leptophyllum
Bog willowherb
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Family: Onagraceae · Type: Herb · Not Native
Epilobium leptophyllum (Bog willowherb) is a non-native California herb in the Onagraceae family, recognized by but bulblet-tipped stolons and persistent hair-tufts diagnostic.
Bog willowherb is a naturalized perennial herb found in northern California Interior, Cascade Range, and central eastern Sierra Nevada regions in boggy meadows, seeps, and damp places at elevations of 800 to 1,630 meters. Flowering from June to September, this plant produces white or pink flowers 3.5 to 7 millimeters long with distinctive thread-like stolons tipped with fleshy bulblets. Growing with erect stems 10 to 100 centimeters tall that are densely strigose, it spreads through unique underground runners. Its leaves are linear to narrowly elliptic, approximately 20 to 75 millimeters long and nearly sessile along the stem. The slender fruit is gray-hairy and reaches 35 to 80 millimeters in length, with a persistent seed hair-tuft that aids in wind dispersal.
Identification and appearance
Key characters: 22 sympatric species but bulblet-tipped stolons and persistent hair-tufts diagnostic
Habitat and range
Habitat: Uncommon. Boggy meadows, seeps, damp places
Elevation: 800-1630 m
Outside California: to British Columbia, Montana, Colorado, native to eastern North America
Bloom period
Epilobium leptophyllum blooms Jun-Sep.
How to tell it apart
vs Penstemon: Epilobium has 4 notched petals and opposite leaves; Penstemon has 5-lobed tubular flowers (snapdragon family).; vs Gambelia: Epilobium has 4 notched petals; Gambelia has 5-lobed tubular snapdragon-like flowers.; vs Fuchsia: Epilobium has notched petals spreading flat; Fuchsia has dangling tubular flowers with protruding stamens.; vs Keckiella: Epilobium has 4 notched petals; Keckiella has 5-lobed tubular snapdragon-like flowers.; vs Diplacus: Epilobium has 4 notched petals; Diplacus has 5-lobed tubular monkey flowers.
Frequently asked questions
Is Epilobium leptophyllum native to California?
No. Epilobium leptophyllum is not native to California (recorded as not native).
When does Epilobium leptophyllum bloom?
Epilobium leptophyllum blooms Jun-Sep.
What plant family does Epilobium leptophyllum belong to?
Epilobium leptophyllum is in the Onagraceae family, genus Epilobium.
What habitat does Epilobium leptophyllum grow in?
Epilobium leptophyllum grows in Uncommon. Boggy meadows, seeps, damp places.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.