Ambrosia eriocentra
Woolly bur-sage
(c) Trevor Van Loon, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Shrub · Native
Ambrosia eriocentra (Woolly bur-sage) is a native California shrub in the Asteraceae family, recognized by hair-tufted spine tips and woolly leaves diagnostic.
Woolly bur-sage is a California native shrub found in the eastern Mojave Desert mountains and desert regions on dry washes and slopes at elevations of 450 to 1,750 meters. Flowering from April to June, this plant produces small greenish flower heads with soft, hairy clusters that are approximately 5 to 7 millimeters in diameter. Growing as a rounded shrub 30 to 180 centimeters tall with gray-brown stems that become less hairy with age, it develops a distinctive spherical shape. Its leaves are lanceolate, 1 to 9 centimeters long, with coarse teeth or lobed edges, appearing gray on the undersides and green on top, and slightly rolled under. The fruit is a distinctive green-brown bur covered in long soft hairs, with 12 to 20 sharp spines near its middle that have hair-like tips.
Identification and appearance
Key characters: 7 sympatric species; hair-tufted spine tips and woolly leaves diagnostic
Habitat and range
Habitat: dry washes and slopes
Elevation: 450-1750 m
Outside California: to northwestern Arizona, southwestern Utah
Bloom period
Ambrosia eriocentra blooms Apr-Jun.
How to tell it apart
vs Artemisia: Ambrosia produces spiny burs as fruits; Artemisia has tiny dry fruits without spines and strongly aromatic foliage.; vs Atriplex: Ambrosia has flower heads in spikes producing spiny burs; Atriplex has inconspicuous flowers with papery bracts and scurfy gray foliage.; vs Baccharis: Ambrosia has both male and female flowers on the same plant; Baccharis has male and female flowers on separate plants.; vs Eriogonum: Ambrosia has greenish flower heads producing spiny burs; Eriogonum has showy clusters of white, pink, or yellow flowers with papery bracts.; vs Salvia: Ambrosia has inconspicuous greenish flowers in the Asteraceae; Salvia has showy tubular lipped flowers typical of mints.
Frequently asked questions
Is Ambrosia eriocentra native to California?
Yes. Ambrosia eriocentra is native to California (recorded as native).
When does Ambrosia eriocentra bloom?
Ambrosia eriocentra blooms Apr-Jun.
What plant family does Ambrosia eriocentra belong to?
Ambrosia eriocentra is in the Asteraceae family, genus Ambrosia.
What habitat does Ambrosia eriocentra grow in?
Ambrosia eriocentra grows in dry washes and slopes.
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.