HPIPM:Absinth wormwood

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Asteranae
Order	Asterales
Family	Asteraceae
Subfamily	Asteroideae
Tribe	Anthemideae
Subtribe	Artemisiinae
Genus	Artemisia

Scientific Name

Artemisia absinthium

Scientific Name Synonyms

Artemisia absinthium ssp. insipida

Common Name

absinth wormwood

Absinth wormwood (Artemisia absinthium)

Author: Michael Moechnig

Adapted from the South Dakota State University Cooperative Extension Weed Control webpage on [http://plantsci.sdstate.edu/weeds/weed_description.cfm?weed=Absinth%20wormwood absinth wormwood

Identification and Life Cycle

Absinth wormwood (Artemisia absinthium) is an aggressive introduced perennial in the aster family (Asteraceae). Absinth wormwood is also called wormwood sage. Stems emerge from buds at the crown of a heavy, fibrous root. Stems are 2 to 4 feet tall, heavily branched, and covered with gray hairs giving it a grayish-green cast. When crushed the stem produces a distinct mint fragrance. Leaves are gray-green, 2 to 5 inches long and are alternate. The lower leaves are deeply divided and upper leaves are linear and less divided. Flowers develop on short stalks and are small, yellow, and compact.

Habitats

Absinth wormwood primarily grows in disturbed areas within grasslands, pastures, and perennial crops.

Impacts

Absinth wormwood contains sesquiterpene lactone absinthin, a substance that can be toxic to other plants. Absinth wormwood is considered a weed in pastureland, cropland, and rangeland.

Biology and Ecology

Absinth wormwood reproduces primarily by seed. Germination occurs on moist soils under a wide range of temperatures. Seedlings can germinate throughout the growing season, from early spring until August. Rosettes form by the end of the first growing season. After the first season, growth begins in early spring with flower stalks developing in July. Flowering occurs in late July and August. Seeds mature in early fall. Absinth wormwood is a prolific seed producer and seeds remain viable in the soil for 3 to 4 years. Consequently, complete control may require a multiple year effort. Seeds are spread by wind, water, and animals, and can also be transported in hay. The above-ground parts of the plant die in late fall, but the crown of the plant produces buds that develop into new shoots each spring.

Management Approaches

Absinth wormwood is an aggressive weed and requires fall or early spring control. Herbicides become less effective as wormwood matures (greater than 8 – 12 inches tall) or during dry periods.

Biological Control

There are no biological control agents available for absinth wormwood at this time.

Mechanical and Cultural Control

Absinth wormwood does not establish well in closed grass stands, and managing pasture and rangeland to maintain vigorous and healthy grass stands can reduce the invasion of absinth wormwood. Summer fallow and fall tillage can prevent establishment of absinth wormwood on cultivated land. Cutting can reduce seed production.

Chemical Control

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.

References

For more information and images please visit IPM Bugwood. http://www.ipmimages.org/search/action.cfm?q=absinth%20wormwood&Start=1&results=29

Additional information was obtained from the following resources:

http://plants.usda.gov/java/profile?symbol=ARAB3

Carey, Jennifer H. 1994. Artemisia absinthium. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/plants/forb/artabs/all.html [2008, December 3]

http://www.agdepartment.com/NoxiousWeeds/pdf/ABSINTHWORMWOOD.pdf