Heterotheca grandiflora
Telegraph weed
Photo by Chez Brungraber
Family: Asteraceae · Type: Herb · Native
Heterotheca grandiflora (Telegraph weed) is a native California herb in the Asteraceae family, recognized by annual habit, large size, ear-like leaf lobes, many rays, and differential pappus.
Telegraph weed is a California native perennial herb found in southern Northwest California, southern Sierra Nevada Foothills, southern Tehachapi, Great Valley, Central Western, Southwestern, and Desert regions in disturbed areas, dry streambeds, and sand dunes at elevations less than 1,100 meters. Flowering from June to October and occasionally throughout the year, this plant produces yellow ray flowers 5 to 8 millimeters long with numerous ray and disk flowers in flat-topped clusters. Growing with generally erect stems 10 to 250 centimeters tall that are densely bristly and glandular, especially toward the branch tips. Its leaves vary from basal rosettes with ovate to elliptic blades to mid-stem lanceolate leaves, with lower leaves clasping and hairy while upper leaves are less hairy and more glandular. The fruits are small, measuring 2 to 5 millimeters long, with ray fruits nearly glabrous and disk fruits slightly strigose.
Identification and appearance
Key characters: 13 sympatric species; distinguished by annual habit, large size, ear-like leaf lobes, many rays, and differential pappus
Habitat and range
Habitat: Disturbed areas, dry streambeds, sand dunes
Elevation: < 1100 m
Outside California: northwestern Mexico, introduced in Arizona, Utah
Bloom period
Heterotheca grandiflora blooms Generally Jun-Oct(+- all year).
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 grandiflora native to California?
Yes. Heterotheca grandiflora is native to California (recorded as native).
When does Heterotheca grandiflora bloom?
Heterotheca grandiflora blooms Generally Jun-Oct(+- all year).
What plant family does Heterotheca grandiflora belong to?
Heterotheca grandiflora is in the Asteraceae family, genus Heterotheca.
What habitat does Heterotheca grandiflora grow in?
Heterotheca grandiflora grows in Disturbed areas, dry streambeds, sand dunes.
Related species
Other California species in the same genus, family, or bioregion.
- Heterotheca monarchensis — Monarch goldenaster
- Heterotheca oregona — Rayless goldenaster
- 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
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.