Mazus pumilus
Japanese mazus

Distribution: Introduced in eastern United States and in scattered locations in southwest Washington and adjacent Oregon.

Habitat: Lawns and wet bottom lands.

Flowers: May - November

Origin: Introduced from Asia

Conservation Status: Not of concern


Annual, branched from the base, the stem up to 15 cm. tall and covered with spreading hairs.


Basal leaves rounded above and narrowed toward the base, up to 4 cm long and 15 mm. wide, irregularly toothed; cauline leaves similar but smaller, opposite.


Inflorescence a naked raceme that is longer than the proper stem, openly 4-10 flowered; calyx 5-cleft to the middle, 4-5 mm. long; corolla bilabiate, 7-10 mm. long, blue-violet, marked with yellow and white, the upper lip short and 2-toothed, the lower lip much larger, 3-lobed; stamens 4, one pair longer; stigmas 2, flattened.



Accepted Name:
Mazus pumilus (Burm. f.) Steenis

Synonyms & Misapplications:
Mazus japonicus (Thunb.) Kuntze [HC]
Additional Resources:

PNW Herbaria: Specimen records of Mazus pumilus in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Mazus pumilus checklist entry.

E-Flora BC: Mazus pumilus atlas page.

CalPhotos: Mazus pumilus photos.

USDA Plants: Mazus pumilus information.

12 photographs:
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