Chaenactis glabriuscula var. megacephala
Big headed yellow chaenactis
Photo: parent species Chaenactis glabriuscula · Photo by Chez Brungraber
Family: Asteraceae · Type: Herb · Native
Chaenactis glabriuscula var. megacephala (Big headed yellow chaenactis) is a native California herb in the Asteraceae family, recognized by large solitary yellow heads on long peduncles.
Big headed yellow chaenactis is a California native annual found in southern Sierra Nevada foothills, San Joaquin Valley, south Coast Ranges, and western Transverse Ranges in dry, often sandy slopes and woodland openings at elevations of 300 to 1,500 meters. Flowering from March to June, this plant produces yellow flowers in heads 1 to 3 per stem, with widely cylindric involucres and corollas 5 to 8 millimeters long. Growing 15 to 40 centimeters tall with generally 1 to 5 erect or ascending stems that branch proximally, it has a delicate, open structure. Its leaves are 1 to 8 centimeters long with flat blades typically 1-pinnately lobed, featuring 2 to 7 pairs of lobes with flat to cylindric tips. The fruit is 5 to 8.5 millimeters long with a pappus of 4 to 5 scales, the longest generally 5 to 8 millimeters.
Identification and appearance
Key characters: 8 sympatric species; key features are large solitary yellow heads on long peduncles
Habitat and range
Habitat: Dry, often sandy slopes, openings in chaparral, woodland
Elevation: 300-1500 m
Bloom period
Chaenactis glabriuscula var. megacephala blooms Mar-Jun.
How to tell it apart
vs Eriophyllum: Eriophyllum has obvious yellow ray flowers; Chaenactis completely lacks rays; vs Lasthenia: Lasthenia has bright yellow rays; Chaenactis rayless with white/purple tubular flowers only; vs Malacothrix: Malacothrix has all strap-shaped flowers and milky sap; Chaenactis all tubular, clear sap; vs Eriogonum: Eriogonum flowers have 6 segments in ball-like clusters; Chaenactis typical composite heads; vs Uropappus: Uropappus has all strap-shaped yellow flowers; Chaenactis all tubular white/purple flowers
Frequently asked questions
Is Chaenactis glabriuscula var. megacephala native to California?
Yes. Chaenactis glabriuscula var. megacephala is native to California (recorded as native).
When does Chaenactis glabriuscula var. megacephala bloom?
Chaenactis glabriuscula var. megacephala blooms Mar-Jun.
What plant family does Chaenactis glabriuscula var. megacephala belong to?
Chaenactis glabriuscula var. megacephala is in the Asteraceae family, genus Chaenactis.
What habitat does Chaenactis glabriuscula var. megacephala grow in?
Chaenactis glabriuscula var. megacephala grows in Dry, often sandy slopes, openings in chaparral, woodland.
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.