Erigeron foliosus var. hartwegii
Hartweg's fleabane
(c) Madeleine Claire, some rights reserved (CC BY), uploaded by Madeleine Claire · licence
Family: Asteraceae · Type: Herb · Native
Erigeron foliosus var. hartwegii (Hartweg's fleabane) is a native California herb in the Asteraceae family, recognized by one-sided leaf arrangement distinctive.
Hartweg's fleabane is a California native perennial found in northern and central Sierra Nevada Foothills in rocky riverbanks and oak woodland at elevations of 100 to 600 meters. Flowering from April to July, this plant produces white to lavender ray flowers with yellow disk centers, with ray flowers 7 to 12 millimeters long. Growing with slender stems 15 to 45 centimeters tall, it develops a clumping habit with stems that are somewhat oriented to one side. Its leaves are narrow, 35 to 80 millimeters long and only 1 to 2 millimeters wide, sparsely covered with stiff hairs and arranged along the stem. The flower heads feature 26 to 50 ray flowers with phyllaries that are densely spreading-hairy and 4 to 6 millimeters long.
Identification and appearance
Key characters: Geographically isolated; one-sided leaf arrangement distinctive
Habitat and range
Habitat: Rocky riverbanks, oak woodland
Elevation: 100-600 m
Bloom period
Erigeron foliosus var. hartwegii blooms Apr-Jul.
How to tell it apart
vs Bellis: Erigeron has double-layered pappus (outer scales + inner bristles); Bellis completely lacks pappus.; vs Symphyotrichum: Erigeron has double pappus (2 layers); Symphyotrichum has single layer of uniform bristles.; vs Corethrogyne: Erigeron has simple unbranched stems; Corethrogyne has branched stems.; vs Pseudognaphalium: Erigeron has flat button-like flower heads; Pseudognaphalium has woolly clustered heads without rays.; vs Artemisia: Erigeron has obvious ray petals around yellow disk; Artemisia lacks ray petals entirely.
Frequently asked questions
Is Erigeron foliosus var. hartwegii native to California?
Yes. Erigeron foliosus var. hartwegii is native to California (recorded as native).
When does Erigeron foliosus var. hartwegii bloom?
Erigeron foliosus var. hartwegii blooms Apr-Jul.
What plant family does Erigeron foliosus var. hartwegii belong to?
Erigeron foliosus var. hartwegii is in the Asteraceae family, genus Erigeron.
What habitat does Erigeron foliosus var. hartwegii grow in?
Erigeron foliosus var. hartwegii grows in Rocky riverbanks, oak 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.