''Eupatorium capillifolium'', or dogfennel (also written "dog fennel"), is a North American perennial

herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition ...

in the family

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 ...

, native to the eastern and south-central

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 U.S. state, states, a Washington, D.C., federal district, five ma ...

. It is generally between 50 cm and 2 meters tall with several stems that fork from a substantial base. The stems and base are covered in leaves so dissected that they resemble branching green threads coming out of the stem in

fractal In mathematics, a fractal is a geometric shape containing detailed structure at arbitrarily small scales, usually having a fractal dimension strictly exceeding the topological dimension. Many fractals appear similar at various scales, as il ...

patterns. When crushed, the leaves and flowers smell rather unpleasant.

Classification

Dogfennel is closely related to ''

Eupatorium compositifolium ''Eupatorium compositifolium'', commonly called Yankeeweed, is a North American herbaceous perennial plant in the family Asteraceae native to the southern United States (from North Carolina to Florida and Texas). Like other members of the ge ...

'' (yankeeweed) and ''

Eupatorium leptophyllum ''Eupatorium leptophyllum'', commonly called false fennel, is a herbaceous perennial plant in the family Asteraceae native to the southeastern United States from Mississippi to the Carolinas. Like other members of the genus ''Eupatorium'', it i ...

'' and some authors consider all of them varieties of ''E. capillifolium''. Others maintain them as three species but consider them a related group, known as dogfennels or the ''Traganthes'' group. They all are characterized by dissected leaves.

Cultivation and uses

Dogfennel thrives on roadsides, in fields and reduced tillage crops, as well as areas that have burned or otherwise been disturbed. It is found in the early to middle ( seral) stages of

ecological succession Ecological succession is the process of change in the species structure of an ecological community over time. The time scale can be decades (for example, after a wildfire) or more or less. Bacteria allows for the cycling of nutrients such as car ...

. It is native to the southern and eastern

, from

Massachusetts Massachusetts (Massachusett language, Massachusett: ''Muhsachuweesut assachusett writing systems, məhswatʃəwiːsət'' English: , ), officially the Commonwealth of Massachusetts, is the most populous U.S. state, state in the New England ...

south to

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, a ...

, and west to

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

and

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

, and also

Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...

and the

Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to 88% of the archi ...

. Unlike insect-pollinated plants in this genus, ''E. capillifolium'' is

wind-pollinated Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including grasses, sedges, and rushes. Other common anemophilous pl ...

. Dogfennel was also known to be planted by

Johnny Appleseed John Chapman (September 26, 1774March 18, 1845), better known as Johnny Appleseed, was an American pioneer nurseryman who introduced apple trees to large parts of Pennsylvania, Ohio, Indiana, Illinois, and Ontario, as well as the northern cou ...

. Dogfennel is eaten by

's scarlet-bodied wasp moth, ''

Cosmosoma ''Cosmosoma'' is a genus of tiger moths in the subfamily Arctiinae. The genus was erected by Jacob Hübner in 1823. Species *''Cosmosoma achemon'' (Fabricius, 1781) *''Cosmosoma achemonides'' Dognin, 1907 *''Cosmosoma admota'' (Herrich-Schäf ...

myrodora''. These moths feed on the plant while mature, to store its toxins and ward off predators.

Control

Dogfennel spreads by both seeds and rootstocks and can grow quite aggressively. It is common in pastures, especially those that are unimproved or overgrazed, and degrades the quality of the pasture by competing with desired forage species. Dogfennel contains

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...

-damaging

pyrrolizidine alkaloid Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine. Pyrrolizidine alkaloids are produced by plants as a defense mechanism against insect her ...

s, so livestock are known to eat all the turf around a stand of it. To remove infestations of dogfennel, the recommended course of action is to mow it before it can seed. It has also been introduced outside its native range, for example in Nepal.

Toxicity

Dogfennel contains pyrrolizidine alkaloids which can cause liver failure.

Medical uses

''Eupatorium capillifolium'' is extracted into an essential oil and has anti-fungal properties. File:Eupatorium capillifolium plant.jpg File:Eupatorium capillifolium leaves.jpg

References

External links

photo of herbarium specimen at Missouri Botanical Garden, collected in Missouri in 1999
{{Taxonbar, from=Q5409948 capillifolium Butterfly food plants Plants described in 1783 Flora of the United States Flora of the Caribbean