Flower:

Flowers are whorled in groups of 3 in a spike-like raceme at the top of a naked stem. There are usually both male and female flowers on the same stem, but sometimes a stem has a single gender. Both genders are about 1/3 inch across with 3 broad white petals. Female flowers have a bulbous light green center, covered in tiny carpels.

Male flowers have a group of yellow stamens in the center. The stamen stalk (filament) is covered in yellow hairs giving it a fuzzy appearance.

Behind the flower are 3 small pale green sepals. At the base of the whorl are 3 triangular to egg-shaped bracts, 1/8 to 1/3 inch long. The bracts shrivel up quickly, the brown, papery remains persisting through fruiting. A plant has 1 or more flowering stems, each with 3 to 6 whorls of flowers. Flower stalks are slender, 1/3 to 1¼ inches long, and about the same length for both male and female flowers.

Leaves and stems:

A rosette of toothless, hairless basal leaves surrounds the flowering stems. Emersed leaves are lance-elliptic to linear, the blade up to 4 inches long and to ¾ inch wide, on 3-sided stalks up to 20 inches long. Rarely blades may have short lobes at the base. Submersed leaves are lance-linear, 6 to 10 inches long, to 1½ inches wide, tapering to a sharp point at the tip, and relatively stiff. This species has stolons (horizontal stems) but not rhizomes.

Fruit:

Fruit is a globular head of beaked seeds up to ¾ inch in diameter; the beak projecting at an upward angle or horizontally from just below the top of the seed.

Notes:

The flowers of Crested Arrowhead are probably the most delicate looking—almost frilly—of the 6 Sagittaria species in Minnesota. Its leaves are most similar to Sessile-fruited Arrowhead (Sagittaria rigida), which also has hairy stamens, but is easily distinguished by its stalkless (or nearly so) female flowers and fruits. Also similar is Grass-leaved Arrowhead (Sagittaria graminea), which is not confirmed present in Minnesota but is just to our east in Wisconsin. It is a rhizomonous species without stolons, its submersed leaves are not stiff, and emersed leaves are more grass-like.