Virginia Tech Weed Identification Guide

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.

Roots: Horizontal rhizomes that are rooted in the soil below.

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

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.

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.