Appearance

Sagittaria sagittifolia is native to Asia and Europe. It is a perennial aquatic herbaceous plant that has become a crop pest around the world. It is very hardy and frost resistant. S. sagittifolia is used in cultivation for the starchy walnut sized tubers it produces.

Foliage

The leaves of S. sagittifolia are held on triangular petioles that vary in length with the depth of the water in which the plant is growing. The hastate leaves are large, very glossy and stand high above the water’s surface. The early, submerged leaves are ribbon like.

Flowers

The white flowers of S. sagittifolia have three petals with a purple spot at their base. There are three flowers in each ring or whorl. The flowers are monoecious and are insect pollinated. S. sagittifolia flowers in mid-summer.

Fruit

Fruits are achenes and ripen through the fall. S. sagittifolia can also reproduce vegetatively from whole, immature plants and from the underground tubers. Its seeds can float easily allowing it to be carried long distances on water currents.

Ecological Threat

Sagittaria sagittifolia is a federally listed noxious weed. It has been introduced to Australia, South America and North America. S. sagittifolia has been reported in Mississippi. The USDA Pest Risk Assessments rates it as medium to high in overall pest risk potential. S. sagittifolia can be found from Sub-arctic to tropical latitudes.

Resources

• Federal Noxious Weed Disseminules of the U.S. - USDA-APHIS

Selected Images

Maps

Invasive Listing Sources

• Federal Noxious Weeds
• Indiana Invasive Species Council - Invasive Plant List
• Indiana Pest Species
• Indiana Prohibited Plant Species
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• New Hampshire Prohibited Aquatic Species
• South Carolina Illegal Aquatic Plants
• South Carolina Plant Pest List
• USDA APHIS Regulated Pest List
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References