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Federal Noxious Weed
TDA Noxious Weed
TPWD Prohibited Exotic Species
Invasive Plant Atlas of the US

NOTE: means species is on that list.

Alternanthera sessilis


Sessile joyweed

Synonym(s): Achyranthes sessilis (L.) Desf. ex Steud. Alternanthera glabra Moq., Gomphrena sessilis L.
Family: Amaranthaceae
Duration and Habit: Annual, Perennial Forb/Herb


Photographer: J.M.Garg
Source: wikipedia.org

Description

A low lying and sprawling herbaceous perennial, A. sessilis can range across the ground from 20-60 meters. Roots will often grow from nodes. Leaves are glabrous and grow directly from the stem. Leaf shapes are typically elliptical, oblong and oblanceolate and can range from 1.12-2.2 cm in length. Inflorescences grow at the axil and are sessile. The inflorescence is composed of small, white, ovate to lanceolate tepals. Fruits are small bladder-like structures containing one lenticular shaped seed. Seeds are roughly 0.9-1.1 mm long. (Flora of North America:Alternanthera sessilis)

Ecological Threat: Covering large areas and very adaptable, A. sessilis can reduce crop yield and infest wetland areas. Plants can block irrigation pipes and canals. (Alternanthera sessilis- Fact Sheet, 2014) It has noxious, prohibited, or quarantine weed status in AL, AR, CA, FL, MA, MN, NC, OR, SC and VT.

Biology & Spread: Can grow in dry areas but can also live partially submerged in water. Seeds are the main reproduction strategy but roots can form at nodes.

History: Likely escaped from aquatic gardens or aquaria.

U.S. Habitat: A. sessilis can survive in both wetlands and agricultural areas and is highly adaptable.

Distribution

U.S. Nativity: Introduced to U.S.

Native Origin: Southern Asia

U.S. Present: AL, AR, FL, GA, LA, MD, MI, SC, TX

Distribution: Southeastern U.S.

Mapping

Invaders of Texas Map: Alternanthera sessilis
EDDMapS: Alternanthera sessilis
USDA Plants Texas County Map: Alternanthera sessilis

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.

Text References

Online Resources

http://www.plants.usda.gov/core/profile?symbol=ALSE4

http://www.inspection.gc.ca/plants/plant-protection/invasive-plants/fact-sheets/alternanthera-sessilis/eng/1331814440546/1331814543527

http://www.hear.org/pier/species/alternanthera_sessilis.htm

http://efloras.org/florataxon.aspx?flora_id=1&taxon_id=200006977

Search Online

Google Search: Alternanthera sessilis
Google Images: Alternanthera sessilis
NatureServe Explorer: Alternanthera sessilis
USDA Plants: Alternanthera sessilis
Invasive Plant Atlas of the United States: Alternanthera sessilis
Bugwood Network Images: Alternanthera sessilis

Last Updated: 2015-07-27 by LBJWC
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