Rohan Wells, National Institute of Water & Atmospheric Research, Bugwood.org

Family: Hydrocharitaceae (Tape-Grass Family)

Synonym(s):

Duration: Perennial

Habit: Herb

Listed by:
Invasive Plant Atlas of the US: 1
Federal Noxious Weed: 1
TDA Noxious Weed: 1
TPWD Prohibited Exotic Species: 1

Description: A rhizomatous, perennial, submerged aquatic plant. It has numerous threadlike roots, which are 'adventitious' (branching from the stem) and, along with rhizomes (horizontal stems in the sediment), anchor it to the bottom. Stems, which can reach the surface, are brittle and sparsely branched, 3-5mm in diameter and curved towards the base (J-shaped). The leaves are 5-20mm long and 2-3mm wide, and occur in alternate spirals along the stem. They generally have tapered tips curving downwards towards the stem, except in low alkalinity water where they are straight. The three-petalled female flowers are very small, clear-white on the surface, and grow on very thin white to almost translucent filament-like stalks.

History:

Biology & Spread:

Ecological Threat: Lagarosiphon major is fast-growing, may totally fill the volume of a large shallow lake (to 3 m deep, fills water control channels, in New Zealand, Lagarosiphon major is a major aquatic weed problem recorded in many lakes,

US Habitat: lakes, riparian zones, water courses, wetlands

Distribution

US Nativity: Cultivated, or not in the U.S.

Native Origin: Native in southern Africa

US States: Happily, Lagarosiphon major does not yet occur in the wild in the United States, as 2008, so far as is known. However, experts have reason to believe that should this plant be introduced to the U.S., the resulting problems could be as consequential as those caused by another plant in the Hydrocharitaceae family, hydrilla (Hydrilla verticillata)

Resembles/Alternatives:

Management:

USE PESTICIDES WISELY: ALWAYS READ THE ENTIRE PESTICIDE LABEL CAREFULLY, FOLLOW ALL MIXING AND APPLICATION INSTRUCTIONS AND WEAR ALL RECOMMENDED PERSONAL PROTECTIVE GEAR AND CLOTHING. CONTACT YOUR STATE DEPARTMENT OF AGRICULTURE FOR ANY ADDITIONAL PESTICIDE USE REQUIREMENTS, RESTRICTIONS OR RECOMMENDATIONS. MENTION OF PESTICIDE PRODUCTS ON THIS WEB SITE DOES NOT CONSTITUTE ENDORSEMENT OF ANY MATERIAL.

Listing Source

Texas Department ofAgriculture Noxious Plant List
Texas Parks and Wildlife Department Prohibited Exotic Species
Invaders Program
Federal Noxious Weed
Union of Concerned Scientists
United States Forest Service Southern Research Station

Text References

Center for Aquatic Invasive Plants. 2009. African elodea. University of Florida. Accessed 19 August 2010 (http://plants.ifas.ufl.edu/node/220).

Data Source

Last Updated: 2009-02-03 by HTG