Brazilian Elodea, Brazilian Water-weed, Common Water-weed

Growth Form:  Forb

General:   Aquatic submersed, perennial herb, very bushy, generally rooted in depths up to 20 feet or drifting, roots slender, white or pale, unbranched; lacks specialized storage organs such as rhizomes or tubers.

Flowers:   White, 0.7 - 0.98 inches across with three petals, male or female; float on or rise above the water's surface while attached to stem.

Fruits and Seeds:   Seeds and female flowers have never been reported from populations in the US. Reproduction from vegetative growth; specialized areas along stem (double nodes, every 6 - 12 whorls) produce new plants if fragmented from stem.

Leaves:   Bright green, 0.8 - 1.18 inches long, up to 0.2 inches broad, usually in whorls of 4 to 6 (8) in short intervals along stem (gives leafy, bushy appearance), leaf edges minutely serrated

Stems or Branches:   Stem cylindrical, single or branched; grows to water surface forming dense mats (profuse branching); adventitious roots produced from specialized nodes on the stem.

Threatens:   Threatens still and flowing freshwater aquatic communities including lakes, ponds, pools, ditches, and quiet streams.

Look-Alikes:   Common Waterweed, Elodea canadensis; leaves in whorls of 3 around the stem (or opposite) without tubers, flower petals absent or small. Non-native Hydrilla verticillata; leaves in whorls of 3 - 8 with tiny spines along the leaf margins. The midrib of each leaf is often reddish. Hydrilla produces tubers (small potato-like structures).

Distribution:   Native to Brazil and to the coastal areas of Argentina and Uruguay. Known from Washington to Massachusetts, California, and Florida. Found in Minnesota in 2007.

Other Links:  

http://www.ecy.wa.gov/programs/WQ/plants/weeds/aqua002.html
http://www.ecy.wa.gov/programs/WQ/plants/weeds/egeria.html
http://www.ppws.vt.edu/scott/weed_id/eldde.htm
http://www.invasivespeciesinfo.gov/aquatics/brazwaterwd.shtml