Hieracium horridum
Prickly hawkweed
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Family: Asteraceae · Type: Herb · Native
Hieracium horridum (Prickly hawkweed) is a native California herb in the Asteraceae family, recognized by prickly hairiness and cauline leaves distinctive.
Prickly hawkweed is a California native perennial found in the Klamath Ranges, high Cascade Range, Sierra Nevada, San Gabriel Mountains, San Bernardino Mountains, San Jacinto Mountains, and Great Basin in rocky places and crevices at elevations of 1,350 to 3,300 meters. Flowering from June to October, this plant produces yellow flowers in numerous heads with 6 to 12 individual florets. Growing with one to several stems from a taproot, reaching 10 to 45 centimeters tall and densely covered in long white or brown hairs. Its cauline leaves are oblong, 3 to 10 centimeters long, positioned alternately along the stem and remaining entire. The plant's distinctive involucre is 6 to 9 millimeters long, slightly cylindric to bell-shaped, with short branched hairs that have black bases.
Identification and appearance
Key characters: 8 sympatric species; prickly hairiness and cauline leaves distinctive
Habitat and range
Habitat: Rocky places, crevices
Elevation: 1350-3300 m
Outside California: Oregon
Bloom period
Hieracium horridum blooms Jun-Oct.
How to tell it apart
vs Pilosella: Pilosella has stolons (runners) spreading along the ground; Hieracium lacks these horizontal stems.; vs Daucus: Daucus has umbel flower clusters and carrot-scented foliage; Hieracium has dandelion-like heads and lacks carrot scent.; vs Adelinia: Adelinia has beaked seeds; Hieracium seeds attach directly to pappus without any beak.; vs Heterotheca: Heterotheca has ray and disk flowers (daisy-like); Hieracium has only strap-shaped flowers.; vs Rafinesquia: Rafinesquia has smooth or sparsely hairy stems; Hieracium is densely long-hairy especially below.
Frequently asked questions
Is Hieracium horridum native to California?
Yes. Hieracium horridum is native to California (recorded as native).
When does Hieracium horridum bloom?
Hieracium horridum blooms Jun-Oct.
What plant family does Hieracium horridum belong to?
Hieracium horridum is in the Asteraceae family, genus Hieracium.
What habitat does Hieracium horridum grow in?
Hieracium horridum grows in Rocky places, crevices.
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.