Alisma spp. (Water plantain)

BONAP indicates, for the family Alismataceae, 6 genera in the U.S. (Alisma, Baldellia, Damasonium, Echinodorus, Helanthium, Sagittaria); three of these occur in Iowa (Alisma, Echinodorus, Sagittaria).

These 3 genera have in common: wet habitat (marshes and lake shores), green sepals that remain during fruiting, white (occasionally reddish) petals that fall soon after flowering, carpels are distinct—one loculared usually with a single ovum and becoming achenes in fruit.

Distribution of Alisma

USDA Plant site: U.S. 5 species; Iowa 3 species.

BONAP site: U.S. 6 species; Iowa 3 species.

VPI site: Iowa 2 species.

Alisma charactistics

See FNA site:

The Alisma species you are most likely to encounter in Iowa are:

Alisma gramineum (Narrowleaf water plantain) - rare in Iowa

Alisma subcordatum (American water plantain)
[syn. Alisma plantago-aquatica]

Alisma triviale (Northern water plantain)