Page authors: Don Knoke, David Giblin
Maianthemum dilatatum
wild lily-of-the-valley, may-lily, two-leaf false Solomon's-seal

Distribution: Occurring west of the Cascades crest and east in the Columbia River Gorge in Washington; Alaska to California, east to northern Idaho.

Habitat: Shady, moist areas, open to dense woods, from sea level to middle elevations in the mountains.

Flowers: May-July

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Bees, flies


Perennial herbs from wide-spreading rhizomes, the erect, unbranched flowering stems 1-3.5 dm. tall.


Leaves cordate, 5-11 cm. long and broad, with slender petioles 2-9 cm. long; those on the flowering stem usually 2, occasionally 1 or 3.


Inflorescence a raceme 3-6 cm. long, usually simple, often with several pedicels at one node; tepals 4, distinct, white, 2.5 mm. long; stamens 4, attached at the base of the tepals, about 1.5 mm. long; pistil 2-celled, style 1, bi-lobed.


Fruit a red berry, globose, 5 mm. long, few-seeded.

Accepted Name:
Maianthemum dilatatum (Alph. Wood) A. Nelson & J.F. Macbr.
Publication: Bot. Gaz. 61: 30. 1916.

Synonyms & Misapplications:
Maianthemum bifolium (L.) F.W. Schmidt var. dilatatum Alph. Wood
Maianthemum bifolium (L.) F.W. Schmidt var. kamtschaticum (J.F. Gmel.) Jeps.
Maianthemum kamtschaticum (J.F. Gmel.) Nakai
Unifolium dilatatum (Alph. Wood) Greene
Unifolium kamtschaticum (J.F. Gmel.) Gorman
Additional Resources:

PNW Herbaria: Specimen records of Maianthemum dilatatum in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Maianthemum dilatatum checklist entry

OregonFlora: Maianthemum dilatatum information

E-Flora BC: Maianthemum dilatatum atlas page

CalPhotos: Maianthemum dilatatum photos

42 photographs:
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