Page authors: Don Knoke, David Giblin
Hemizonella minima
smallhead tarplant, least tarweed, small-head tarweed, smallhead tarweed

Distribution: Occurring chiefly east of the Cascades crest in Washington; southern British Columbia to California, east to Montana and Nevada.

Habitat: Dry, open areas in sagebrush, grasslands, and ponderosa pine forest openings.

Flowers: May-July

Origin: Native

Conservation Status: Not of concern


Slender, widely-branched annual, up to 1 dm. tall, occasionally taller, somewhat fine-hairy and glandular.


Leaves linear or linear-oblong, 1-2 cm long and 1-2.5 mm. wide, all opposite.


Heads in the forks of the stem and in small terminal clusters; involucre of 5 or fewer bracts, 2-4 mm. high, bearing tack-shaped, sticky glands; ray flowers minute, their achenes compressed at right angles to a radius through the head and enclosed by the involucral bracts; disk flowers usually solitary, yellow, and enclosed by the united bracts of the receptacle.


Achenes somewhat compressed at right angles to a radius of the head.

Accepted Name:
Hemizonella minima (A. Gray) A. Gray
Publication: Proc. Amer. Acad. Arts. 9: 189. 1874.

Synonyms & Misapplications:
Hemizonia minima A. Gray
Madia minima (A. Gray) D.D. Keck [HC]
Additional Resources:

PNW Herbaria: Specimen records of Hemizonella minima in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Hemizonella minima checklist entry.

E-Flora BC: Hemizonella minima atlas page.

CalPhotos: Hemizonella minima photos.

USDA Plants: Hemizonella minima information.

19 photographs:
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