Distribution: Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
Habitat: Sloughs and slow-moving, fresh water.
Flowers: April-July
Origin: Native
Growth Duration: Annual, Perennial
Conservation Status: Not of concern
Pollination: Wind, self-pollination
Small aquatic herbs, the stems 0.5-4 dm. long, emersed to emergent, with small, membranous ridges between the leaf bases.
Emersed leaves linear, 1-nerved, 0.5-2.5 mm. long; floating and emergent leaves broadly obovate, 3-nerved, up to 1 cm. wide.
Flowers imperfect, sessile in the leaf axils, each consisting of a single pistil or 1 stamen or both; styles 2, distinct, 1-5 mm. long, persistent; floral bracts present.
Carpels 2, obovate, 0.7-1.2 mm. long and broad, wingless, pitted with small, shallow pits.
Publication: Fl. Amer. Sept. (Pursh) 1: 3. 1813.
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var. bolanderi – Bolander's different-leaved water-starwort
Occurring west of the Cascades crest in Washington; Alaska to California. -
var. heterophylla – different-leaved water-starwort Occurring chiefly west of the Cascades crest in Washington; Alaska to California, east across most of North America to the Atlantic Coast.
PNW Herbaria: Specimen records of Callitriche heterophylla in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Callitriche heterophylla checklist entry
OregonFlora: Callitriche heterophylla information
E-Flora BC: Callitriche heterophylla atlas page
CalPhotos: Callitriche heterophylla photos
