Heterotheca oregona
Rayless goldenaster, Rayless Goldenaster
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Family: Asteraceae · Type: Subshrub · Native
Heterotheca oregona (Rayless goldenaster) is a native California subshrub in the Asteraceae family, recognized by uniquely distinguished by complete lack of ray flowers (discoid heads).
Rayless goldenaster is a California native perennial herb found in rocky or disturbed habitats across California's coastal and interior regions. Flowering from summer to fall, this plant produces discoid flower heads without ray flowers, with clusters of small yellow disk flowers 7.5 to 14 millimeters long. Growing 20 to 100 centimeters tall with ascending to erect stems that branch proximally and distally, it develops a variable canopy with glandular and bristly stems. Its mid-stem leaves are oblanceolate, entire, and range from nearly glabrous to densely bristly, with distal leaves progressively wider. The plant produces small fruits 2 to 5 millimeters long, with an outer pappus less than half a millimeter and inner pappus scales 4.5 to 6.5 millimeters long.
Identification and appearance
Key characters: 13 sympatric species; uniquely distinguished by complete lack of ray flowers (discoid heads)
How to tell it apart
vs Grindelia: Heterotheca has multi-layered bracts; Grindelia bracts curve backward and flower buds are sticky-resinous.; vs Isocoma: Heterotheca has conspicuous yellow ray petals; Isocoma has only disk flowers (no rays).; vs Erigeron: Heterotheca rays are yellow and 3-12mm; Erigeron rays are white/purple/pink and typically numerous.; vs Laennecia: Heterotheca has showy 3-12mm yellow rays; Laennecia has tiny inconspicuous white rays.; vs Verbascum: Heterotheca has composite flower heads with bracts; Verbascum has simple 5-petaled flowers on tall spikes.
Frequently asked questions
Is Heterotheca oregona native to California?
Yes. Heterotheca oregona is native to California (recorded as native).
What plant family does Heterotheca oregona belong to?
Heterotheca oregona is in the Asteraceae family, genus Heterotheca.
Related species
Other California species in the same genus, family, or bioregion.
- Heterotheca oregona var. compacta — Compact oregon goldenaster
- Heterotheca oregona var. oregona — Oregon false goldenaster
- Heterotheca oregona var. rudis — Oregon false goldenaster
- Heterotheca oregona var. scaberrima — Oregon false goldenaster
- Heterotheca sessiliflora — Sessileflower goldenaster
- Heterotheca sessiliflora subsp. bolanderi
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.