USDA Plant site: U.S. 28 species; Iowa 8 species.
BONAP site: U.S. 30 species; Iowa 8 species.
VPI site: Iowa 7 species.
The Sagittaria species are found along muddy shores or in shallow water. Only one species is wide spread and common in Iowa (S. latifolia) which is abundant in the NE half of the state. The others are infrequent or rare or clustered in small regions, especially around lakes.
Sagittaria latifolia - Common arrowhead
The following links go offsite:
Sagittaria australis - Longbeak arrowhead
Sagittaria brevirostra - Shortbeak arrowhead
Sagittaria calycina - Hooded arrowhead
Sagittaria cristata - Crested arrowhead
Sagittaria cuneata - Arumleaf arrowhead
Sagittaria graminea - Grassy arrowhead
Sagittaria rigida - Sessilefruit arrowhead