
Calla palustris
Calla palustris (Bog Arum, Marsh Calla) in a shallow channel made by beavers through a shrub carr/sedge meadow. Associated species include Canary Grass (Phalaris arundinacea), Common Duckweed (Lemna minor), and Small Yellow Water Crowfoot (Ranunculus gmelinii).

Calla (Bog Arum, Marsh Calla) is a genus of flowering plant in the family Araceae, containing the single species Calla palustris. It is native to cool temperate regions of the Northern Hemisphere, in central, eastern and northern Europe (France and Norway eastward), northern Asia and northern North America (Alaska, Canada, northeastern contiguous United States).