Alismataceae: Sagittaria latifolia
Dakota and Lakota peoples, often harvested for their starchy, edible roots of broadleaf arrowhead. The tubers, known as duck potatoes, were a traditional food source for many Native American peoples. The plant provides habitat and food for waterfowl and other wildlife and is used in wetland restoration and water filtration.
Description
Sagittaria latifolia is a perennial aquatic or semi-aquatic herb growing from a thick, edible, tuberous rhizome. It typically reaches 30 to 100 cm tall with erect, smooth, hollow stems. Leaves are variable but often sagittate (arrow-shaped), broadly ovate to lanceolate, measuring 10 to 30 cm long and 5 to 15 cm wide. Leaf bases are lobed and clasp the stem, with long cylindrical petioles 20 to 60 cm in length. The blades float on the surface or are emergent, being held above the water. The inflorescence is a consists of two to four whorls of flowers blooming from June to September. The plants are monoecious, producing separate male and female flowers on the same plant. Typically, the lower whorls of the inflorescence bear female flowers, while the upper whorls have male flowers. Each flower has three white petals, 15 to 25 mm long and 10 to 15 mm wide, often featuring a yellow center. Flowers are subtended by three green sepals, lanceolate to ovate, about 8 to 12 mm long and 3 to 5 mm wide, with smooth margins and pointed tips. Male flowers have numerous stamens (9–15), with filaments 5 to 7 mm long and yellow anthers about 3 to 4 mm long. Pistilate flowers has multiple carpels (20 or more) each with a slender style ending in a small stigma, arranged in the center of the receptacle. Fruits are aggregates of achenes, 2 to 4 mm long, forming rounded heads, 3 cm in diameter, that mature in late summer to fall. Broadleaf arrowhead is native to South Dakota, commonly found in shallow freshwater wetlands, ponds, lakes, and slow-moving streams.