What plant is that?

Click on photo below to view larger image

Northern water plantainNorthern water plantain-- leavesNorthern water plantain-- peduncleNorthern water plantain -- fruit
Northern water plantain -- close up of flower -- habitat

Top row 2nd photo from left: © Peter M. Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.inf
Other five photos:© Katy Chayka, via Minnesota Wildflowers, https://www.minnesotawildflowers.inf

The mystery plant for September 2021 is a perennial which grows 10-30” tall. The leaves are long-petioled with elliptical blades, 3-8cm long by 2-12cm in width. The flowers have 3 white petals, 3 sepals and 6 stamens. The petals are yellow in color at the base and twice as long as the sepals. The scape, which is a leafless peduncle, rises from ground level to a height of 10-30”. This plant is found in wet habitats, marshes and ponds.

It’s. . .

Botanical Name:
  
Alisma triviale
Common Name:
   Northern Water Plantain
Family:
   Alismataceae (Water Plantain Family)
Habitat:
   Marshes, muddy shorelines, ditches