Sagittaria is a genus of about 30 species of aquatic plants whose members go by a variety of common names, including
arrowhead,
duck potato,
katniss,
Omodaka (沢瀉 in Japanese),
swamp potato,
tule potato, and
wapato (or
wapatoo). Most are native to South, Central, and North America, but there are also some from Europe, Africa, and Asia.
(Wikipedia)