Invasive Plants Conference

More than 200 professionals committed to the eradication of noxious weeds will gather in Washington DC next week (Feb 26-March 3) to highlight the economic and environmental threats posed by invasive plants.  Participants in the 7th annual National Invasive Weed Awareness Week will contact members of Congress, showcase new strategies to control invasive plants and discuss the formation of Cooperative Weed Management Areas throughout the country.  Nelroy Jackson, chair of the Invasive Weed Awareness Coalition, said "Because weeds know no borders, we must set aside our own organizational boundaries and work together to address problems collaboratively." 

During the week of the conference, the US Botanic Garden, at the foot of Capitol Hill, will have exhibits on display that demonstrate how to identify invasive plants and outline successful strategies to combat them. According to conference organizers, invasive plants multiply rapidly, crowding out native species and causing damage to natural ecosystems. Nine of the 21 most endangered ecosystems in the US are significantly threatened by exotic invasions; the US spends more than $120 billion annually in an effort to control more than 800 invasive species.

Some of the invaders:

Water Chestnut(Trapa L., Trapa natans) at right, which grows in fresh water anywhere and is found in MD, DE, PA, NY, MA, VT.  It reduces oxygen levels, potentially increases fish kills, and forms thick mats that limit boating, fishing, and other recreational activities.

Garlic Mustard (Allaria petiolata) which grows along roadsides, floodplains and forests throughout the Midwest and Northeast.  Its spread has led to the decline of the West Virginia white butterfly because chemicals in the plant are toxic to the butterfly's eggs.

Giant Reed (Arundo L., Arundo donax), which grows from Texas to California and in the East from Virginia to Kentucky and Missouri southward.  It chokes water supplies from riversides and streams and reduces the habitat for the Least Bell's vireo, a bird on the federal endangered species list.

Orange Hawkweed (Hieracium aurantiacum L.), which grows from Alaska to Maine in pastures, abandoned farmland, open woodlands, and meadows.  It inhibits the growth of other plants by producing toxic chemicals in surrounding soil.

(photo: Steve Hurst, USDA, NRCS, PLANTS Database)