Calycadenia villosa
Dwarf calycadenia
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Family: Asteraceae · Type: Herb · Native
Conservation status: CNPS 1B.1
Calycadenia villosa (Dwarf calycadenia) is a native California herb in the Asteraceae family, recognized by . Restricted to central/southern Outer South Coast Ranges.
Dwarf calycadenia is a rare (CNPS 1B.1) California native annual found in central Coast Ranges and Sierra Cascade foothills in dry, rocky hills, grasslands, and foothill woodland openings at elevations of 250 to 850 meters. Flowering from May to September, this plant produces white to pale pink flowers with ray flowers up to 5 millimeters long, each with a narrow central lobe and asymmetric lateral lobes. Growing 10 to 45 centimeters tall with reddish stems that are rigid and scabrous, with dense long hairs and few to many ascending or spreading branches. Its proximal leaves are often persistent, measuring 2 to 5 centimeters long, with narrow linear to lance-elliptic form. The plant produces heads with 1 to 3 flowers per node, each with distinctive peduncle bracts 3 to 12 millimeters long.
Identification and appearance
Key characters: 0 sympatric species - geographically isolated. Restricted to central/southern Outer South Coast Ranges
Habitat and range
Habitat: Dry, rocky hills, ridges, grassland, openings in foothill woodland
Elevation: 250-850 m
Bloom period
Calycadenia villosa blooms May-Sep.
Conservation status
CNPS 1B.1
How to tell it apart
vs Hemizonia: Calycadenia rays deeply fringed; Hemizonia rays shallowly lobed with ray fruits beaked.; vs Osmadenia: Calycadenia covered with tack glands; Osmadenia completely lacks sticky glands.; vs Deinandra: Calycadenia rays deeply split; Deinandra rays shallowly lobed or entire.; vs Madia: Calycadenia has tack glands and deeply split rays; Madia lacks tack glands, different ray shape.; vs Holocarpha: Calycadenia has tack glands (not pit glands); Holocarpha has pit-gland depressions on bracts.
Frequently asked questions
Is Calycadenia villosa native to California?
Yes. Calycadenia villosa is native to California (recorded as native).
When does Calycadenia villosa bloom?
Calycadenia villosa blooms May-Sep.
What plant family does Calycadenia villosa belong to?
Calycadenia villosa is in the Asteraceae family, genus Calycadenia.
Is Calycadenia villosa rare or endangered?
Calycadenia villosa carries California Rare Plant Rank 1B.1, state rank S3.
What habitat does Calycadenia villosa grow in?
Calycadenia villosa grows in Dry, rocky hills, ridges, grassland, openings in foothill woodland.
Related species
Other California species in the same genus, family, or bioregion.
- Calycadenia fremontii — Fremont's calycadenia
- Calycadenia hooveri — Hoover's calycadenia
- Calycadenia micrantha — Small-flowered calycadenia
- Calycadenia mollis — Soft calycadenia
- Calycadenia multiglandulosa — Rosin weed
- Calycadenia oppositifolia — Butte county calycadenia
- Calycoseris parryi — Yellow tack-stem
- Calycoseris sp. — Tack-stem
- Calycoseris wrightii — White tack-stem
- Carduus acanthoides subsp. acanthoides — Plumeless thistle
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.