''Eupatorium macrocephalum''
Less. aka pompom weed, is a cosmopolitan perennial plant belonging to the family of
Asteraceae
The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...
and regarded as an invasive weed in some countries. It is native to the southern
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
,
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
,
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
and was introduced to
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
.
It is classed as a principal weed in
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
. In South Africa it has been cultivated as an ornamental, is often found on roadsides, and has become of concern for its invading of undisturbed climax grassland and wetlands since the 1960s.
[ It is closely related to Siam weed, and is one of some 268 species in the genus.
This species is rhizomatous with erect stems to 1.3 m tall, and has stem and leaves covered in rough, bristly hairs. It forms dense rosettes of leaves at ground level, suppressing the germination and growth of other species, at the same time producing ]allelochemical
Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have ben ...
s which adversely affect the growth of neighbouring plants. The plant dies back annually to its root crown, and survives veldfires over the winter period. Its leaves are light green in colour, lanceolate-elliptic in shape, and measure 8 cm x 2 cm. Leaf margins are serrate, the teeth becoming smaller away from the stalk. Flower heads are surrounded by lanceolate, purplish bracts some 8 mm in length. Flowers are large, pink and showy, and exceed the bracts by 6–8 mm. Mature achenes are black and 5 mm long with a pappus of simple bristles.
Moths of the genus '' Adaina'' and in particular '' Adaina microdactyla'' (Hübner), have been investigated as possible biological control agents. Species in the genus include flower borers, leaf feeders and also species that induce stem galls which provide food and accommodation for larvae and pupae. Research at Cedara College of Agriculture
Cedara College of Agriculture is an agricultural college and research station near Howick, KwaZulu-Natal, South Africa, founded partly by Thomas Robertson Sim. The foundation stone of the "School of Agriculture and Forestry" was laid on 28 April ...
has found a rust fungus, ''Puccinia eupatorii'', which invades the seeds and kills the whole plant, including the roots. This rust fungus is specific to ''E. macrocephalum'' and would therefore be ideal as a biological control. Other potential insect agents include a stem-galling thrips, ''Liothrips
''Liothrips'' is a genus of thrips with almost 300 described species. They are ordered into three subgenera, ''Epiliothrips'' (2 species), ''Liothrips'' (262 species) and ''Zopyrothrips'' (25 species).
The Clidemia thrips ''Liothrips urichi'' is ...
'' sp., and the moth '' Cochylis campuloclinium''.
Material from this species has been analysed, resulting in the identification of six triterpenes, one diterpene glycoside
In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...
ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
, six steroid
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...
s, one flavonoid
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Chemically, flavonoids ...
known as cirsilol, and six cinnamic acids derivatives.
The name ''Eupatorium macrocephalum'' was first published in January 1830 by Christian Friedrich Lessing
Christian Friedrich Lessing (10 August 1809 – 13 March 1862) was a German botanist who was a native of Syców, Groß Wartenberg, Niederschlesien. He was a brother to painter Carl Friedrich Lessing (1808–1880), and a grandnephew of poet Gotthold ...
in Linnaea 5(1): 136–137. 1830.Anatolia
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
, while 'macrocephalum' means 'large-headed' and refers to the inflorescence.
Synonyms
*''Campuloclinium macrocephalum var. strigosum'' DC.
*''Chromolaena pratensis'' Gardner
*''Eupatorium albertinae'' Ant.Molina
*''Eupatorium denudatum'' Chodat
*''Eupatorium donianum'' Hook. & Arn.
*''Eupatorium macrocephalum var. angustifolium'' Baker
*''Eupatorium macrocephalum var. stigmatosum'' (Chodat) Hassl.
*''Eupatorium macrocephalum var. strigosum'' (DC.) Baker
*''Eupatorium stigmatosum'' Chodat llegitimate
*''Eupatorium stigmatosum var. subcalvatum'' Chodat
*''Eupatorium stigmatosum var. violaceum'' Chodat
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References
External links
How to control the weed
Campuloclinium macrocephalum
{{DEFAULTSORT:macrocephalum, Eupatorium
Eupatorium