Page author: David Giblin
Lysimachia thyrsiflora
tufted yellow-loosestrife

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

Habitat: Swamps, lakes and ditches.

Flowers: May-July

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bees, flies


Erect, glabrous herbs from creeping rhizomes, the flowering stems 2-8 cm. tall, with fine, purplish-black spots almost throughout.


Lowermost leaves sessile and greatly reduced; upper leaves opposite, nearly sessile, linear-lanceolate to narrowly elliptic, long-acuminate, up to 15 cm. long, narrowed gradually to the base.


Flowers crowded and sub-sessile in dense, slender, pedunculate racemes in the axils of 2 or 3 pairs of larger leaves near mid-stem; calyx lobes 5, united only at the base, spotted, glabrous, lanceolate, 2-3 mm. long; corolla divided nearly to the base, the 5 lobes linear-lanceolate, pale yellow, twice the length of the calyx; stamens 5, exerted, opposite the corolla lobes, the filaments distinct, glabrous.


Capsule 2.5 mm. long, spotted, opening by 5 valves.

Accepted Name:
Lysimachia thyrsiflora L.
Publication: Sp. Pl. 1: 147. 1753.

Synonyms & Misapplications:
Lysimachia capitellata Raf.
Lysimachia subcapitata Raf.
Lysimachusa thyrsiflora (L.) Pohl
Naumburgia thrysiflora (L.) Rchb.
Nummularia thrysiflora (L.) Kuntze
Thyrsanthus palustris Schrank
Additional Resources:

PNW Herbaria: Specimen records of Lysimachia thyrsiflora in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Lysimachia thyrsiflora checklist entry.

OregonFlora: Lysimachia thyrsiflora information.

E-Flora BC: Lysimachia thyrsiflora atlas page.

CalPhotos: Lysimachia thyrsiflora photos.

USDA Plants: Lysimachia thyrsiflora information.

27 photographs:
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