Burke: Sagittaria latifolia vs. Sagittaria graminea

	Sagittaria latifolia	Sagittaria graminea
	common arrowhead, duck potato, wapato	grassy arrowhead
Habit	Aquatic, scapose, tuber-bearing perennials from strong rhizomes, the scapes up to 5 dm. long.
Leaves	Leaves mostly emersed, but often submerged and the blades floating; blades sagittate or hastate, up to 2.5 dm. long and nearly as broad; submerged leaves sometimes bladeless and greatly elongate, 4-10 mm. broad.
Flowers	Flowers in 2-8 whorles of 3 in bracteate racemes, the bracts 5-10 mm. long, blunt, hooded; pedicles 1-5 cm. long, ascending, in both the pistillate flowers (lower whorles) and staminate flowers.(upper whorles), or the plants sometimes monoecious; sepals 3, 5-10 mm. long, persistent; petals 3, white, twice as long as the sepals; stamens more than 20; pistils many on a globose receptacle.
Fruits	Achenes 2.5-4 mm. long, winged, with a stylar beak strongly up-turned, 0.5-1.5 mm. long.

	Sagittaria latifolia	Sagittaria graminea
Flowering time	July-September	June-August
Habitat	Ditches, ponds, lakes, swampy areas.	Wetlands, ponds, and lakes
Distribution	Occurring on both sides of the Cascades in Washington; Vancouver Island, British Columbia to central California; central North America to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]	Occurring west of the Cascades crest in Washington; Great Plains to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]
Origin	Native	Introduced from central and eastern North America
Conservation status	Not of concern	Not of concern
Sibling taxa	S. cuneata, S. graminea, S. platyphylla, S. rigida, S. subulata	S. cuneata, S. latifolia, S. platyphylla, S. rigida, S. subulata
Subordinate taxa		S. graminea ssp. graminea
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Sagittaria graminea

common arrowhead, duck potato, wapato

grassy arrowhead

Habit

Aquatic, scapose, tuber-bearing perennials from strong rhizomes, the scapes up to 5 dm. long.

Leaves

Leaves mostly emersed, but often submerged and the blades floating;

blades sagittate or hastate, up to 2.5 dm. long and nearly as broad; submerged leaves sometimes bladeless and greatly elongate, 4-10 mm. broad.

Flowers

Flowers in 2-8 whorles of 3 in bracteate racemes, the bracts 5-10 mm. long, blunt, hooded; pedicles 1-5 cm. long, ascending, in both the pistillate flowers (lower whorles) and staminate flowers.(upper whorles), or the plants sometimes monoecious;

sepals 3, 5-10 mm. long, persistent;

petals 3, white, twice as long as the sepals;

stamens more than 20;

pistils many on a globose receptacle.

Fruits

Achenes 2.5-4 mm. long, winged, with a stylar beak strongly up-turned, 0.5-1.5 mm. long.

Sagittaria latifolia

Sagittaria graminea

Flowering time

July-September

June-August

Habitat

Ditches, ponds, lakes, swampy areas.

Wetlands, ponds, and lakes

Distribution

Occurring on both sides of the Cascades in Washington; Vancouver Island, British Columbia to central California; central North America to the Atlantic Coast.

[WildflowerSearch map]

[BONAP county map]