Ageratum houstonianum

Ageratum houstonianum, Photo: Michael Lahanas

Cladus: Eukaryota
Regnum: Plantae
Divisio: Magnoliophyta
Classis: Magnoliopsida
Ordo: Asterales
Familia: Asteraceae
Subfamilia: Asteroideae
Tribus: Eupatorieae
Genus: Ageratum
Species: Ageratum houstonianum


Ageratum houstonianum Mill.


* USDA, NRCS. 2006. The PLANTS Database, 6 March 2006 (

Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

* Gard. dict. ed. 8: Ageratum no. 2. 1768
* USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. [1]

Ageratum houstonianum Blue Horizon , Ageratum houstonianum Weißer Schnitt,

Vernacular names
English: Flossflower, Bluemink
日本語: オオカッコウアザミ
한국어: 불로화
Lietuvių: Meksikinis žydrūnis
Polski: Żeniszek meksykańsk
Русский: Агератум Гаустона
Türkçe: Vapurdumanı


Ageratum houstonianum (Flossflower, Bluemink; syn. Ageratum mexicanum Hort.) is a cool-season annual plant often grown as a bedding plant in gardens. Herb 0.3-1 m high, leaves ovate to triangular 2-7 cm long, and flowers are usually blue (though sometimes white, pink, or purple), the heads borne in dense corymbs. The ray flowers are threadlike, leading to the common name.[1]

Native to Central America and adjacent parts of Mexico, but has become an invasive weed in other areas.[2][3]

Ageratum has evolved an ingenious method of protecting itself from insects; it produces a precocene compound which interferes with the normal function of the corpus allatum, the organ responsible for secreting juvenile hormone. This chemical triggers the next molting cycle to prematurely develop adult structures, and can render most insects sterile if ingested in large enough quantities.[4]


Ageratum houstonianum is toxic to grazing animals, causing liver lesions.[5][6] It contains pyrrolizidine alkaloids.[7]

Weed risk

A. houstonianum is prone to becoming a rampant environmental weed when grown outside of its natural range. It has become an invasive weed in the eastern USA, Australia, Europe, Africa, China, Japan and New Zealand.[8]


1. ^ New South Wales Flora Online, Ageratum houstonianum [1]
2. ^ "Ageratum houstonianum". Flora of North America.
3. ^ Species profile [2]
4. ^ I. Kiss et al. (September, 1988), "Biological activity of precocene analogues on Locusta migratoria", Cellular and Molecular Life Sciences 44: 790–792, doi:10.1007/BF01959168
5. ^ Acamovic, T., Stewart, C.S., Pennycott, T.W.,"Poisonous Plants and Related Toxins", 2004
6. ^ Noa, M., Sanchez, L.M., Durand, R., "Ageratum houstonianum toxicosis in Zebu cattle", Veterinary and human toxicology, 2004, vol.46, no4, pp.193-195.
7. ^ Wiedenfeld H, Andrade-Cetto A., "Pyrrolizidine alkaloids from Ageratum houstonianum Mill.", Phytochemistry, 2001 Aug, pp1269-71[3]
8. ^ Global Compendium of Weeds, Ageratum houstonianum (Asteraceae) [4]

* Bailey, L. H. (2005). Manual of Gardening (Second Edition).. Project Gutenberg Literary Archive Foundation.

Plants Images

Biology Encyclopedia

Source: Wikispecies: All text is available under the terms of the GNU Free Documentation License


Scientific Library -