Hesperevax acaulis var. ambusticola
Fire evax
(c) Roger Raiche, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Herb · Native
Hesperevax acaulis var. ambusticola (Fire evax) is a native California herb in the Asteraceae family, recognized by growth form and leaf shape.
Fire evax is a California native annual found in southern North Coast Ranges, central and southern Sierra Nevada foothills, southern Sierra Nevada, southwestern San Joaquin Valley, eastern San Francisco Bay Area, southern Coast Ranges, Santa Barbara and southern California coastal areas in clearings, barren slopes, and burned landscapes at elevations of 200 to 1,300 meters. Flowering from April to June, this plant produces small white flowers in tiny heads 2 to 2.5 millimeters wide. Growing with multiple prostrate stems just 0.5 to 2 centimeters tall, it forms delicate ground-hugging clusters. Its leaves are small and distinctive, typically 4 to 7 millimeters long, with obovate to rounded blades that spread outward from the stem. In areas recently burned, this diminutive annual creates delicate ground cover with its compact, spreading growth form.
Identification and appearance
Key characters: 4 sympatric species; distinguished by growth form and leaf shape
Habitat and range
Habitat: Clearings, barren slopes, burns
Elevation: 200-1300 m
California counties: Santa Clara, San Diego, Butte, Tehama, Tuolumne, Fresno, San Luis Obispo, Mendocino, Santa Barbara, Lake, Calaveras, Monterey, Santa Cruz, San Benito
Bloom period
Hesperevax acaulis var. ambusticola 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. ambusticola native to California?
Yes. Hesperevax acaulis var. ambusticola is native to California (recorded as native).
When does Hesperevax acaulis var. ambusticola bloom?
Hesperevax acaulis var. ambusticola blooms Apr-Jun.
Where in California does Hesperevax acaulis var. ambusticola grow?
Hesperevax acaulis var. ambusticola occurs in Santa Clara, San Diego, Butte, Tehama, Tuolumne, Fresno, San Luis Obispo, Mendocino and other counties, at elevations of 200-1300 m.
What plant family does Hesperevax acaulis var. ambusticola belong to?
Hesperevax acaulis var. ambusticola is in the Asteraceae family, genus Hesperevax.
What habitat does Hesperevax acaulis var. ambusticola grow in?
Hesperevax acaulis var. ambusticola grows in Clearings, barren slopes, burns.
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.