Sagittaria platyphylla
delta arrowhead

Distribution: Occurring west of the Cascades crest in Washington; Washington and Portland, Oregon area, otherwise south-central U.S., and in scattered locations in central and northeastern U.S., where native.

Habitat: Pond and lake margins.

Flowers: June-August

Origin: Introduced from the southeastern U.S.

Growth Duration: Perennial

Conservation Status: Not of concern

Pollination: Generalist


Herbaceous stoloniferous perennials with floating leaves, up to 150 cm, corms present.


Submersed or emersed, margins entire; leaves under water phyllodial, sessile, flattened above and beneath, up to 26 cm long and 0.5 cm broad; leaves above water petiolate, petioles somewhat triangular and 21-70.5 cm long, blade linear-ovate to ovate, 4.6-16.4 cm long and 0.7-6.1 cm broad.


Inflorescences bracteate racemes with 3-9 whorls, above water, 2.5-10 cm long and 2-4.5 cm broad; peduncles 22-60 cm long; bracts connate greater than ΒΌ total length, lanceolate, 2-5.5 mm, delicate, not papillose; fruiting pedicels spreading to bending backwards, cylindric to 0.5-3 cm; flowers imperfect, to 1.8 cm in diameter; sepals 3, curving backward to spreading, not encasing the flower or fruiting head, persistent; petals 3, white, deciduous; filaments widened, longer than anthers, pubescent; anthers 2-chambered, splitting longitudinally; pistillate flowers pedicellate, sterile stamens absent.


Fruiting heads 0.7-1.2 cm in diameter; achenes oblanceoloid with no abaxial keel, 1.2-2 mm long and 0.8-1.2 mm broad, beaked; faces tuberculate, wings 0, glands 0; beak lateral, horizontal to erect, 0.3-0.6 mm.

Accepted Name:
Sagittaria platyphylla (Engelm.) J.G. Sm.
Publication: N. Amer. Sagittaria. 29. 1894.

Synonyms & Misapplications:
Sagittaria graminea Michx. var. platyphylla Engelm.
Additional Resources:

PNW Herbaria: Specimen records of Sagittaria platyphylla in the Consortium of Pacific Northwest Herbaria database

WA Flora Checklist: Sagittaria platyphylla checklist entry

OregonFlora: Sagittaria platyphylla information

E-Flora BC: Sagittaria platyphylla atlas page

CalPhotos: Sagittaria platyphylla photos

27 photographs:
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