Madia glomerata
Mountain tarweed
(c) Matt Lavin, some rights reserved (CC BY-SA) · licence
Family: Asteraceae · Type: Herb · Native
Madia glomerata (Mountain tarweed) is a native California herb in the Asteraceae family, recognized by high elevation, tightly clustered heads, often rayless flowers, and free paleae.
Mountain tarweed is a California native annual found in the Klamath Ranges, northern California High Sierra, Sierra Nevada, San Bernardino Mountains, and Great Basin in meadows and open disturbed sites with sandy or gravelly soils at elevations of 1,050 to 2,700 meters. Flowering from June to September, this plant produces green-yellow to purple flowers in tightly grouped heads that are occasionally arranged in flat-topped clusters. Growing 0.5 to 12 decimeters tall with soft-hairy and glandular stems that have lateral branches sometimes exceeding the main stem, it displays distinctive yellow or black glandular hairs. Its leaves are linear to lance-linear, measuring 2 to 10 centimeters long and 2 to 7 millimeters wide, with a delicate, sparse structure. The fruit is notable for its black, dull, compressed seeds that lack a beak, with ray and disk fruits appearing similar.
Identification and appearance
Key characters: 6 sympatric species; distinguished by high elevation, tightly clustered heads, often rayless flowers, and free paleae
Habitat and range
Habitat: Meadows, open or disturbed sites, often sandy or gravelly soils
Elevation: (0)1050-2700 m
Outside California: to British Columbia, Saskatchewan, Montana, South Dakota, Wyoming, Colorado, New Mexico, scattered to Alaska, Maine
Bloom period
Madia glomerata blooms Jun-Sep.
How to tell it apart
vs Anisocarpus: Madia has absolutely no pappus on disk flowers; Anisocarpus has 5-21 scales forming a pappus on disk flowers.; vs Deinandra: Madia has ray fruits completely hidden by bracts and no disk pappus; Deinandra has exposed ray fruits and disk pappus present.; vs Layia: Madia has bright yellow rays and no disk pappus; Layia often has white or bicolored rays and hairy disk pappus.; vs Hemizonia: Madia has fruits completely wrapped by bracts; Hemizonia has fruits only partly enclosed by bracts.; vs Lagophylla: Madia has yellow rays and no pappus; Lagophylla has white rays and scale-like pappus on disk flowers.
Frequently asked questions
Is Madia glomerata native to California?
Yes. Madia glomerata is native to California (recorded as native).
When does Madia glomerata bloom?
Madia glomerata blooms Jun-Sep.
What plant family does Madia glomerata belong to?
Madia glomerata is in the Asteraceae family, genus Madia.
What habitat does Madia glomerata grow in?
Madia glomerata grows in Meadows, open or disturbed sites, often sandy or gravelly soils.
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.