Page authors: Don Knoke, David Giblin
Murdannia keisak

Distribution: Occurring west of the Cascades crest in the Lower Columbia River corridor in Washington; southwestern Washington and adjacent northwestern Oregon; also in southeastern United States.

Habitat: Ditches, swales and swamps, often in water.

Flowers: August-October

Origin: Introduced from Asia

Conservation Status: Not of concern


Annual herbs with long-trailing, decumbent shoots.


Leaves alternate, sessile, the blades linear-oblong to linear-lanceolate, 1.5-7 cm. long and 0.2-1 cm. wide, glabrous.


Inflorescences terminal and in upper leaf axils, of 1-several, 1-flowered cymes, solitary or in fascicles; flowers perfect, radially symmetrical, 1 cm. wide; sepals 3, distinct, subequal, 5-6 mm. long; petals 3, lilac to purple or pink or white, 5-8 mm. long; fertile stamens 3, the filaments bearded; sterile stamens 3.


Capsules 5-9 mm. long.

Accepted Name:
Murdannia keisak (Hassk.) Hand.-Mazz.
Publication: Symb. Sin. 7: 1243. 1936.

Synonyms & Misapplications:
Aneilema keisak Hassk.
Additional Resources:

PNW Herbaria: Specimen records of Murdannia keisak in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Murdannia keisak checklist entry.

E-Flora BC: Murdannia keisak atlas page.

CalPhotos: Murdannia keisak photos.

USDA Plants: Murdannia keisak information.

12 photographs:
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