Water Willow/Waterwillow - Justicia americana

Other Name: American Water Willow [Virginia].
Family: Acanthaceae [Nelson].
Flowers: "Flowers orchid-like, white or light violet, with purple spots or other markings in the throat. Lower petal elongate with two elongate, twisted lateral petals. Flowers usually in small clusters." Blooms June - October. [Nearctica.com, Inc.].
Plant: 1 - 3 feet in height [Nearctica.com, Inc.].

Sources

Nearctica.com, Inc. (2003). Water willow.
Nelson, B.Weedy plants of the U.S.: Exotic, invasive and problem plants.
Va. Tech. Virginia Tech weed identification guide.
Photos: Courtesy of S. Peregrine Johnson.

Habitat: Found along the banks of or in the shallow waters of rivers, ponds, and lakes.

Growth: A perennial from rhizomes that is capable of forming large colonies. Water willow is primarily found along the shorelines or in shallow water of lakes, ponds, or streams [Virginia Tech].

Leaves: Arranged oppositely along the stem and are elliptic to linear in outline, approximately 6 inches long. Leaves have a distinctive white mid-vein that runs the length of the entire leaf [Virginia Tech].

Benefits: Considered a nuisance in some situations. It can reduce erosion along shorelines and stream banks subjected to wave action and flow and provides habitat for fish and invertebrates [Nelson].