Hesperevax acaulis var. robustior
Big evax
(c) Ken-ichi Ueda, some rights reserved (CC BY), uploaded by Ken-ichi Ueda · licence
Family: Asteraceae · Type: Herb · Native
Hesperevax acaulis var. robustior (Big evax) is a native California herb in the Asteraceae family, recognized by size and growth habit.
Big evax is a California native annual found in the Klamath Ranges, northern Coast Ranges, northern inner Coast Ranges, Cascade Range foothills, Sierra Nevada foothills, northern Great Valley, and southern Coast Ranges on slopes, flats, swales, and canyon openings at elevations of 60 to 1,100 meters. Flowering from April to June, this plant produces small white flower heads approximately 3 to 4 millimeters wide, nestled close to the ground. Growing with extremely short stems generally 2 to 7 centimeters tall, it forms compact clusters with minimal branching. Its leaves are oblanceolate to obovate, measuring 12 to 22 millimeters long and 2 to 4 millimeters wide, with erect or slightly spreading tips. The fruit is typically 1 to 1.6 millimeters long, contributing to this diminutive plant's delicate structure.
Identification and appearance
Key characters: 4 sympatric species; distinguished by size and growth habit
Habitat and range
Habitat: Slopes, flats, swales, canyons, path edges, openings or under shrubs
Elevation: 60-1100 m
California counties: Tehama, Butte, Colusa, Humboldt, Tuolumne, Stanislaus, Amador, Mendocino, Tulare, Calaveras, Yolo, El Dorado, Placer, Napa, Shasta, Monterey
Outside California: to southwestern Oregon
Bloom period
Hesperevax acaulis var. robustior blooms Apr-Jun.
How to tell it apart
vs Ancistrocarphus: Hesperevax has erect, flat, blunt-tipped bracts; Ancistrocarphus has inward-hooked spine-like tips.; vs Filago: Hesperevax has heads nestled in leaf clusters; Filago has cone-shaped heads on visible stems.; vs Logfia: Hesperevax has flat-tipped erect bracts; Logfia has mushroom-shaped heads with spreading outer bracts.; vs Stylocline: Hesperevax has enlarged flat-tipped bracts; Stylocline has tiny heads hidden in dense woolly mats.; vs Micropus: Hesperevax lacks prominent petal-like bracts; Micropus has 4-6 conspicuous spoon-shaped outer bracts.
Frequently asked questions
Is Hesperevax acaulis var. robustior native to California?
Yes. Hesperevax acaulis var. robustior is native to California (recorded as native).
When does Hesperevax acaulis var. robustior bloom?
Hesperevax acaulis var. robustior blooms Apr-Jun.
Where in California does Hesperevax acaulis var. robustior grow?
Hesperevax acaulis var. robustior occurs in Tehama, Butte, Colusa, Humboldt, Tuolumne, Stanislaus, Amador, Mendocino and other counties, at elevations of 60-1100 m.
What plant family does Hesperevax acaulis var. robustior belong to?
Hesperevax acaulis var. robustior is in the Asteraceae family, genus Hesperevax.
What habitat does Hesperevax acaulis var. robustior grow in?
Hesperevax acaulis var. robustior grows in Slopes, flats, swales, canyons, path edges, openings or under shrubs.
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.