marsh calla

It is a rhizomatous herbaceous perennial plant growing in bogs and ponds. The leaves are rounded to heart-shaped, 6–12 cm (2+1⁄4–4+3⁄4 in) long on a 10–20 cm (4–8 in) petiole, and 4–12 cm (1+1⁄2–4+3⁄4 in) broad. The greenish-yellow inflorescence is produced on a spadix about 4–6 cm (1+1⁄2–2+1⁄4 in) long, enclosed in a white spathe. The fruit is a cluster of red berries, each berry containing several seeds. The plant is very poisonous when fresh due to its high oxalic acid content, but the rhizome (like that of Caladium, Colocasia, and Arum) is edible after drying, grinding, leaching and boiling.

It is native to cool temperate regions of the Northern Hemisphere, in central, eastern and northern Europe (France and Norway eastward, but not Britain), northern Asia and northern North America (Alaska, Canada, and northeastern contiguous United States).