Micranthes howellii
Howell's saxifrage
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Family: Saxifragaceae · Type: Herb · Native
Conservation status: CNPS 4.3
Micranthes howellii (Howell's saxifrage) is a native California herb in the Saxifragaceae family, recognized by geographic restriction and inflated filaments diagnostic.
Howell's saxifrage is a California native perennial found in the Klamath Ranges on moist ledges and rock crevices at elevations below 900 meters. Flowering from February to April, this plant produces delicate white flowers in small clusters of 5 to 15 blooms. Growing with slender stems 5 to 20 centimeters tall that develop short rhizomes, it forms compact clumps in rocky habitats. Its leaves are oblong to ovate, 2 to 6 centimeters long, with coarse rounded or sharp teeth and tapered bases. The plant produces two distinct seed capsules (follicles) as its fruit.
Identification and appearance
Key characters: 11 sympatric species; geographic restriction and inflated filaments diagnostic
Habitat and range
Habitat: Moist ledges, crevices
Elevation: < 900 m
California counties: Del Norte, Siskiyou
Outside California: southwestern Oregon
Bloom period
Micranthes howellii blooms Feb-Apr.
Conservation status
CNPS 4.3
How to tell it apart
vs Saxifraga: Micranthes has all leaves unlobed/entire; Saxifraga has at least some leaves lobed or divided.; vs Romanzoffia: Micranthes has basal rosettes and 2 pistils; Romanzoffia has trailing stems and funnel-shaped flowers.; vs Boykinia: Micranthes has 2 separate pistils forming follicles; Boykinia has 1 pistil forming a capsule.; vs Calyptridium: Micranthes has 2 pistils and 5 petals; Calyptridium has 1 pistil and 2 petals.; vs Verbascum: Micranthes has basal rosettes with small flowers; Verbascum has tall spikes with large fuzzy flowers.
Frequently asked questions
Is Micranthes howellii native to California?
Yes. Micranthes howellii is native to California (recorded as native).
When does Micranthes howellii bloom?
Micranthes howellii blooms Feb-Apr.
Where in California does Micranthes howellii grow?
Micranthes howellii occurs in Del Norte, Siskiyou, at elevations of < 900 m.
What plant family does Micranthes howellii belong to?
Micranthes howellii is in the Saxifragaceae family, genus Micranthes.
Is Micranthes howellii rare or endangered?
Micranthes howellii carries California Rare Plant Rank 4.3, state rank S3.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.