Watershield

Brasenia schreberi

Weed Description
Aquatic floating perennial from rhizomes with distinctive purple stems and leaf undersurfaces. All submerged portions of the plant are also covered in a jelly-like substance. Primarily a weed of poorly-managed lakes or ponds that most commonly occurs in water up to about 5 feet deep. Watershield is found in the eastern United States from Florida to Canada, and also in Oregon and California.

Leaves
Alternate, floating, oval to elliptic in outline, and approximately 4 1/2 inches long and 2 1/2 inches wide. Leaves are green and shiny on the upper surface and purple on the lower surface. The undersides of the leaves are covered with a thick, jelly-like substance. Leaves occur on petioles that range from 4 to 12 inches in length.

Stems
Purple, branched, and may reach 6 feet in length. All submerged stems are covered with a jelly-like substance.

Flowers
Small (10 to 15 mm in diameter), emersed, purple, and occur on single stalks that open at the water surface. Flowers consist of 3 to 4 sepals and petals and 12 to 36 stamens.

Fruit
Club-shaped, leathery, and containing 1 or 2 seeds.

Roots
Horizontal rhizomes that are rooted in the soil below.

Identifying Characteristics
Rooted, floating plants with oval leaves that are green on the upper surface and purple on the lower surface. Additionally, the jelly-like material that covers all submerged portions of the plant helps to distinguish this weed from most other aquatic weeds.

Office of Programs

University of Missouri

Watershield

Brasenia schreberi