Aquatic Plant Identification Manual for Washington's Freshwater Plants
Floating Leaved Rooted Plants
|Species:||Brasenia schreberi Gmel., water-shield, dollar bonnet, water target|
Water-shield is identified by the thick coating of gelatinous slime covering the young stems, buds, and the undersides of young leaves. The long reddish leaf stalks are attached to the centers of the floating oval leaves, giving them an umbrella-like appearance. Water-shield flowers are small, purplish, and rise slightly above the water, but are not particularly showy. Because of the floating leaves, some taxonomists consider water-shield to be in the water-lily family (Nymphaeaceae)
Leaf: Oval leaves (4-12 cm long and 3-8 cm wide) float on the water surface. The leaves have purple undersides with long, centrally-attached leaf-stalks up to 2 m long. A slimy gelatinous substance usually covers the stalks and underside of young leaves and stems.
Stem: Arise from submersed, branching, reddish creeping rhizomes.
Flower: The 5-20 cm long flower stalks each bear a single purplish flower with 3 sepals and 3 (4) similar-looking petals. Each flower measures up to 2.5 cm across and is elevated slightly above the water surface. Blooms May to September.
Fruit: Each flower produces 4-18 separate narrowly egg-shaped, leathery fruits between 6-8 mm long. Each fruit usually contains 2 seeds. They ripen underwater and decay to release seeds.
Root: Slender, branched, creeping rhizomes.
Propagation: Rhizomes, seeds, winter buds.
Importance of plant: The rhizomes and leaves have been used for food and medicinal purposes by Native Americans. The Japanese use the young leaves and stems in salads. Provides habitat for fish and aquatic insects; seeds and vegetation are eaten by waterfowl.
Distribution: Throughout most of the United States and southern Canada. Also occurs in Central America, Cuba, Africa, East Asia and Australia.
Habitat: Shallow ponds, lakes, and slow-moving streams. It grows in water 0.5-3 m deep.
May be confused with: Fragrant water-lily (Nymphaea odorata), some floating-leaved pondweeds (Potamogeton spp.), or yellow floating heart (Nymphoides peltata) but only water-shield is covered by a slimy coating with the stem attached at the center of an oval leaf. Water-lilies have showy white or pink flowers and leaves cleft to the stalk. Floating-leaved pondweeds have the stem attached at the leaf edge and yellow floating heart has yellow flowers with fringed edges.
Photographs: Brasenia schreberi, closeup showing flowers
Line Drawings: Brasenia schreberi