Page author: David Giblin
Lythrum hyssopifolia
hyssop loosestrife

Distribution: Scattered locations on both sides of the Cascades in Washington; British Columbia south to California; eastern North America.

Habitat: Moist, disturbed areas.

Flowers: May-September

Origin: Introduced

Growth Duration: Annual

Conservation Status: Not of concern


Glabrous, pale glaucous-green annual, the stems simple or branched, 1-4 dm. tall, erect or nearly prostrate, somewhat angled.


Leaves alternate, or some of the lower ones opposite, linear to oblong, 1-2.5 cm. long and 1-8 mm. broad, entire.


Flowers perfect, solitary and sessile in the upper leaf axils; calyx tube 4-5 mm. long, with 5-7 lobes about 0.5 mm. long, and linear appendages about twice as long alternating with the lobes; petals 5-7, white to rose, 2-3.5 mm. long, attached to the top of the calyx tube; stamens inserted in the calyx tube.


Capsule elongate, 2-celled.

Accepted Name:
Lythrum hyssopifolia L.
Publication: Sp. Pl. 1: 447. 1753.

Synonyms & Misapplications:
(none provided)
Additional Resources:

PNW Herbaria: Specimen records of Lythrum hyssopifolia in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Lythrum hyssopifolia checklist entry.

E-Flora BC: Lythrum hyssopifolia atlas page.

CalPhotos: Lythrum hyssopifolia photos.

USDA Plants: Lythrum hyssopifolia information.

23 photographs:
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