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JOE-PYE WEED

NOMENCLATURE

Other Names:

Scientific Name: Eupatorium maculatum L.

 Plant Family: Compositae

GENERAL INFORMATION

Botanical Description: herbaceous

 Stems: erect, 2 - 6 feet high, purple spotted

 Leaves: thick, oval to lance-shaped, coarsely toothed, often in whorls around stem

 Roots: fibrous

 Flowers: pink or purple composite flat-topped heads, borne in many-branched clusters on long flower stems, bloom July - September

 Seeds: oblong, narrow, 5-angled, may have tiny bristles

 Seedling: Seed leaves are oblong and less than 0.5 inches long. Subsequent leaves are opposite, hairy, and may be yellow-green. Veins are prominent on the underside of leaves, and tissue between veins may be wrinkled. The second and following pairs of leaves are up to 2.5 inches long. Leaf pairs are up to an inch apart on a thick, hairy, rough stem.

ECONOMIC IMPORTANCE

LIFE CYCLE

Reproduction: perennial

Propagation:

Dispersal:

DISTRIBUTION

State: Common in moist soils throughout Wisconsin..

 National: Found throughout much of the United States.

 Origin: May be native to American tropics.

ENVIRONMENTAL FACTORS

Common on ditchbanks, wild marsh, and a variety of other wetland habitats. May occur along cranberry drainage ditches, bed edges, and in old marshlands adjacent to beds. Thrives in moist calcareous soils.

SCOUTING PROCEDURE/ET

While scouting a cranberry bed for disease and insect pests, identify weed populations as they arise. Note the specie(s) of weed present as well as the population level relative to field area. Example: 20% yarrow, 30% boneset and joe-pye weed mix.

REFERENCES

Dana, M. 1987. Cranberry Weeds in Wisconsin. Department of Horticulture, University of Wisconsin-Madison. Madison, Wisconsin. p. 2.

 

Gleason, H. A. 1952. Illustrated Flora of the United States and Adjacent Canada. Vol 3. Lancaster Press, Lancaster, Pennsylvania. p. 4486.

Kummer, A. P. 1951. Weed Seedlings. The University of Chicago Press, Chicago, U.S.A. p. 306.

 

Kummer, L. D., T. G. Dittl, and T. D. Planer. 1993. Wisconsin Cranberry Weeds. Wisconsin Cranberry Board, Wisconsin Rapids, Wisconsin. p. 12.

 

McGregor, R. L. 1986. Flora of the Great Plains. University Press of Kansas, Lawrence, Kansas. p. 933-934.

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