Sagittaria graminea

Sagittaria graminea, the grassy arrowhead or grass-leaved arrowhead, is an aquatic plant species native to eastern North America.

Description

It is a perennial herb up to tall with narrow, grass-like leaves about in length and wide. A very thin flower-bearing stalk raises to about above water. The flowers are about wide, with three petals and three sepals; typically the upper flowers only have stamens, while lower flowers have only pistils. The seeds appear in a head about 1.5 cm wide.

Subspecies

A long list of varietal and subspecific names have been proposed over the years. Most have either been elevated to the species level or relegated to synonymy. As of April 2014, only two are recognized:

Sagittaria graminea subsp. graminea
Sagittaria graminea subsp. weatherbiana R.R.Haynes & Hellq.

Distribution and habitat

The species is known from every Canadian province from Ontario to Newfoundland, and every US state from the Great Plains to the Atlantic, plus Colorado, New Mexico and Cuba. It is considered naturalized in Washington state and in Vietnam. It grows in wet areas such as marshes and the banks of rivers and lakes.