Verbascum bombyciferum
Giant silver mullein
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Family: Scrophulariaceae · Type: Annual · Not Native
Verbascum bombyciferum (Giant silver mullein) is a non-native California annual in the Scrophulariaceae family.
Giant silver mullein is a naturalized annual found in northern coastal California's Sonoma County in dry streambeds within oak woodland at an elevation of 140 meters. Flowering in June, this plant produces pale yellow flowers in dense terminal racemes, with blossoms 20 to 30 millimeters long nestled in long woolly hairs. Growing with robust stems 50 to 150 centimeters tall and densely covered in white wool-like hairs, it develops striking silvery-white foliage. Its large basal leaves reach up to 40 centimeters long and 20 centimeters wide, with an ovate or obovate shape and slightly crenate edges, completely covered in soft tomentose hair. The fruit is an ovoid capsule 6 to 8 millimeters long, with distinctive stamens featuring white or yellow-hairy upper filaments.
Identification and appearance
Key characters: Co-occurs with 3 species; key differentiator is extremely dense woolly indumentum and clustered flowers embedded in hairs
Habitat and range
Habitat: dry streambed in oak woodland
Elevation: 140 m
Outside California: native to Turkey
Bloom period
Verbascum bombyciferum blooms Jun.
How to tell it apart
vs Stachys: Verbascum has nearly radial flowers in tall spikes; Stachys has bilateral flowers in whorled clusters.; vs Heterotheca: Verbascum has 5-petaled flowers with fuzzy stamens; Heterotheca has composite flower heads with ray and disk flowers.; vs Croton: Verbascum has showy yellow petaled flowers; Croton has tiny flowers without petals.; vs Oenothera: Verbascum has 5 stamens and fuzzy stalks; Oenothera has 8 stamens and smooth flower parts.; vs Dipsacus: Verbascum has individual flowers along spike; Dipsacus has flowers in dense, spiny, rounded heads.
Frequently asked questions
Is Verbascum bombyciferum native to California?
No. Verbascum bombyciferum is not native to California (recorded as not native).
When does Verbascum bombyciferum bloom?
Verbascum bombyciferum blooms Jun.
What plant family does Verbascum bombyciferum belong to?
Verbascum bombyciferum is in the Scrophulariaceae family, genus Verbascum.
What habitat does Verbascum bombyciferum grow in?
Verbascum bombyciferum grows in dry streambed in oak woodland.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.