Page authors: Don Knoke, David Giblin
Tripleurospermum inodorum
false chamomile, false mayweed, scentless mayweed

Distribution: Occurring in scattered locations on both sides of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.

Habitat: Noxious weed in fields and waste ground in eastern Washington.

Flowers: June-September

Origin: Introduced from Europe

Growth Duration: Annual

Conservation Status: Not of concern


Glabrous annual, biennial or occasionally perennial, nearly scentless herb, 1-6 dm. tall.


Leaves 2-8 cm. long, bipinnatifid, the ultimate segments mostly elongate, linear or liner-filiform.


Heads several or numerous, the disk 8-15 mm. wide; involucral bracts dry, in 2 series, the margins translucent; rays 12-25, white, 6-13 mm. long; disk flowers yellow, 5-toothed; receptacle hemispheric, naked; pappus a short crown.


Achenes roughened, with 2 marginal and 1 ventral thickened ribs.

Accepted Name:
Tripleurospermum inodorum (L.) Sch. Bip.
Publication: Tanaceteen. 32. 1844.

Synonyms & Misapplications:
Matricaria inodora L. [HC]
Matricaria maritima L. ssp. inodora (L.) Soó
Matricaria perforata Mérat
Tripleurospermum maritimum (L.) W.D.J. Koch ssp. inodorum (L.) Applequist
Tripleurospermum perforatum (Mérat) M. Lainz
Additional Resources:

PNW Herbaria: Specimen records of Tripleurospermum inodorum in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Tripleurospermum inodorum checklist entry.

E-Flora BC: Tripleurospermum inodorum atlas page.

CalPhotos: Tripleurospermum inodorum photos.

USDA Plants: Tripleurospermum inodorum information.

37 photographs:
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