Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Sagittaria or "arrowhead" is a genus of about 30 species of aquatic plants whose members go by a variety of common names, including arrowhead, duck potato, iz-ze-kn, katniss, kuwai, swan potato, tule potato, and wapato (or wapatoo). Most are native to South America, Central America, and North America, but there are also some from Europe and Asia. Several species bear tubers edible as a starchy root vegetable that are collected from the wild or cultivated as crops in North America and East Asia. Stock often stoloniferous and tuberiferous. Leaves aerial, floating or submerged. Flowers unisexual or polygamous, in umbela, racemes or panicles with female or hermaphrodite flowers at the base and male flowers above or occasionally with the flowers all male or all female.