Horkelia rydbergii
Rydberg's horkelia
Photo by Chez Brungraber
Family: Rosaceae · Type: Herb · Native
Horkelia rydbergii (Rydberg's horkelia) is a native California herb in the Rosaceae family, recognized by matted habit and appressed hairs.
Rydberg's horkelia is a California native perennial found in the Tehachapi Mountains in meadows, streambanks, and pine forests at elevations of 1,200 to 2,800 meters. Flowering from June to August, this plant produces white flowers in clusters with 8 to 40 blossoms. Growing with gray-green, matted stems 10 to 70 centimeters tall that have ascending to appressed hairs, it forms a low, spreading habit. Its compound leaves feature 7 to 14 leaflets on each side, each wedge-shaped and bearing 5 to 10 teeth toward the base, with dense hair coverage giving the plant a soft, silvery appearance. The small flowers have petals 4 to 5.5 millimeters long, arranged in an open, delicate inflorescence.
Identification and appearance
Key characters: 2 sympatric species; key features are matted habit and appressed hairs
Habitat and range
Habitat: Meadows, streambanks, under pines
Elevation: 1200-2800 m
California counties: San Bernardino, Los Angeles, Kern, Ventura, Mariposa
Bloom period
Horkelia rydbergii blooms Jun-Aug.
How to tell it apart
vs Drymocallis: Horkelia has exactly 10 stamens and white-pink flowers; Drymocallis has 20+ stamens and yellow-white flowers.; vs Erodium: Horkelia has pinnate leaves and rose-family flowers; Erodium has lobed/divided leaves and long-beaked fruits.; vs Phacelia: Horkelia has rose-family flowers with separate petals; Phacelia has bell-shaped fused corollas with protruding stamens.; vs Potentilla: Horkelia has exactly 10 stamens and flattened filaments; Potentilla has 20+ stamens and thread-like filaments.; vs Ivesia: Horkelia has flat leaves with 2-15 separated leaflets; Ivesia has cylindrical bottlebrush leaves with overlapping leaflets.
Frequently asked questions
Is Horkelia rydbergii native to California?
Yes. Horkelia rydbergii is native to California (recorded as native).
When does Horkelia rydbergii bloom?
Horkelia rydbergii blooms Jun-Aug.
Where in California does Horkelia rydbergii grow?
Horkelia rydbergii occurs in San Bernardino, Los Angeles, Kern, Ventura, Mariposa, at elevations of 1200-2800 m.
What plant family does Horkelia rydbergii belong to?
Horkelia rydbergii is in the Rosaceae family, genus Horkelia.
What habitat does Horkelia rydbergii grow in?
Horkelia rydbergii grows in Meadows, streambanks, under pines.
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.