Sagittaria lancifolia:
Bulltongue arrowhead
Sagittaria lancifolia L.: Bulltongue arrowhead, duck potato. Alismataceae (water-plantain family).
Native perennial. Can grow in shallow to fairly deep water, or in very moist soil. The strong, spongy leaf stalks emerge fan-wise from seed or from the thick, knobby rhizome to a height of 30 in (80 cm), holding the robust lance-shaped leaves upright. Leaves lack the arrowhead shape of many Sagittaria; there are no leaf-base extensions on either side of the stalk. The firm leaf blade is a long slender oval, 10 - 25 in (25 - 64 cm) long and 1.5 - 4 in (3.75 - 10 cm) wide, pointed at the tip, and tapering gradually into the leaf stalk at the base. There is a ridged or keeled midrib down the center of both sides of the leaf blade; 2 or 3 additional main veins may be seen paralleling this one. The showy white flowers are borne on tall (to 5 ft; 1.5 m) leafless stalks, usually in whorls of three. Flowers have three short broad petals attached by a narrow strip or "claw" of tissue to a center of many thread-like yellow parts. The flattened-sphere or button-like fruits, indented in the middle, are firm and rough textured. Large starchy corms are produced at the ends of rhizomes.