(Spreng.) King & H.Rob.
Ageratina adenophora (syn. Eupatorium adenophorum) is a species of flowering plant in the daisy family known by many common names, including eupatory, sticky snakeroot, crofton weed, and Mexican devil.
Ageratina adenophora is a perennial herbaceous shrub that may grow to 1 or 2 metres (3.3 or 6.6 ft) high. It has opposite trowel-shaped serrated leaves that are 6–10 cm (2.4–3.9 in) long by 3–6 cm (1.2–2.4 in) in width. The small compound flowers occur in late spring and summer, and are found in clusters at the end of branches. Each flowerhead is up to 0.5 cm in the diameter and creamy white in colour. They are followed by a small brown seed with a white feathery 'parachute'.
Distribution and habitat
It is native to Mexico, but it is known in many other parts of the world as an introduced species and often a noxious weed. It has caused great economic loss in agriculture in southwestern China, and is threatening the native biodiversity there. It was first inadvertently introduced to Yunnan around 1940, and its rapid spread is due in part to its allelopathic competition with other plant species. It also a weed in Australia, where it was introduced to Sydney in 1904. It has spread along the coastline of New South Wales and southern Queensland. It is rated a Class 4 Noxious Weed under the NSW Noxious Weeds Act of 1993.
Ageratina adenophora has also spread in Hawaii and the mainland USA, where it is recognised as a weed in ten states of the South and Southwest.
Elsewhere it is an invasive species in many tropical and subtropical countries, including northeastern India, China, Sri Lanka, Nigeria, Southeast Asia, Australia, New Zealand, the Pacific Islands, the Canary Islands, and South Africa.
The plant can spread vegetatively, that is the stems can sprout roots and grow upon contact with earth. The seed is also carried by the wind or water and colonises disturbed areas, such as fields and areas near human habitation, readily. Seed may also be transported on animals and in soil.
- Wolff, Mark A. (1999). Winning the war of Weeds: The Essential Gardener's Guide to Weed Identification and Control. Kenthurst, NSW: Kangaroo Press. p. 17. ISBN 0-86417-993-6.
- Baruah, N. C.; Sarma, J. C.; Sarma, S.; Sharma, R. P. "Seed germination and growth inhibitory cadinenes from Eupatorium adenophorum Spreng". J. Chem. Ecol. 1994, 20, 1885–1892.
- "Plants Profile – Ageratina adenophora (Spreng.) King & H. Rob. sticky snakeroot". USDA website. U.S. Department of Agriculture. 2008. Archived from the original on 6 October 2008. Retrieved 2008-09-20.
- "Ageratina adenophora". University of California website. University of California. Retrieved 2008-09-20.
- Cronk, Q. C. B. & Fuller, J. L. (1995) Plant invaders: the threat to natural ecosystems. Chapman & Hall, London
- Wang, R. & Wang, Y.-Z. (2006) Invasion dynamics and potential spread of the invasive alien plant species Ageratina adenophora (Asteraceae) in China. Diversity and Distributions, 12, 397-408