Alisma

About

Alisma is a genus of flowering plants in the family Alismataceae, members of which are commonly known as water-plantains. The genus consists of aquatic plants with leaves either floating or submerged, found in a variety of still water habitats around the world. The flowers are hermaphrodite, and are arranged in panicles, racemes, or umbels. Alisma flowers have six stamens, numerous free carpels in a single whorl, each with 1 ovule, and subventral styles. The fruit is an achene with a short beak.

Summary from Wikipedia