Helianthella castanea
Diablo helianthella, Diablo Helianthella
(c) Stan Shebs, some rights reserved (CC BY-SA) · licence
Family: Asteraceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Helianthella castanea (Diablo helianthella) is a native California herb in the Asteraceae family, recognized by easily distinguished by large flower heads with prominent leaf-like bracts.
Diablo helianthella is a rare (CNPS 1B.2) California native perennial found in northern Central Coast and northern San Francisco Bay bioregions in open, grassy sites at elevations of 200 to 1,300 meters. Flowering from April to June, this plant produces yellow ray flowers with bright yellow disk centers in large sunflower-like heads up to 4 centimeters in diameter. Growing with stems 10 to 50 centimeters tall that range from smooth to coarsely hairy, it develops distinctive leaf-like outer bracts that curve dramatically around the flower head. Its leaves are elliptic, varying from narrow to wide, with long petioles measuring 2 to 6 centimeters across. The fruit is an obovate seed 8 to 10 millimeters long, often without pappus awns.
Identification and appearance
Key characters: 1 sympatric species; easily distinguished by large flower heads with prominent leaf-like bracts
Habitat and range
Habitat: Open, grassy sites
Elevation: 200-1300 m
Bloom period
Helianthella castanea blooms Apr-Jun.
Conservation status
CNPS 1B.2
How to tell it apart
vs Wyethia: Both basal and stem leaves prominent vs. mostly large basal leaves with smaller stem leaves in Wyethia.; vs Helianthus: Consistently perennial in mountains vs. often annual in disturbed lowlands.; vs Arnica: Leaves mostly opposite up stem vs. mostly alternate in Arnica.; vs Eriophyllum: Large sunflower heads and broad leaves vs. small heads and narrow/divided leaves in woolly sunflower.; vs Helenium: Large basal leaf rosette present vs. basal leaves absent in Helenium.
Frequently asked questions
Is Helianthella castanea native to California?
Yes. Helianthella castanea is native to California (recorded as native).
When does Helianthella castanea bloom?
Helianthella castanea blooms Apr-Jun.
What plant family does Helianthella castanea belong to?
Helianthella castanea is in the Asteraceae family, genus Helianthella.
Is Helianthella castanea rare or endangered?
Helianthella castanea carries California Rare Plant Rank 1B.2, state rank S2.
What habitat does Helianthella castanea grow in?
Helianthella castanea grows in Open, grassy sites.
Related species
Other California species in the same genus, family, or bioregion.
- Helianthella sp.
- Helianthella californica — California helianthella
- Helianthella californica var. californica — California helianthella
- Helianthella californica var. nevadensis — California helianthella
- Helianthella californica var. shastensis — Shasta helianthella
- Helianthus annuus — Common sunflower
- Helianthus bolanderi — Bolander's sunflower
- Helianthus californicus — California sunflower
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.