Rudbeckia hirta

by Erik Boulier

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Taxa:
Common Name..............Black-eyed Susans

Order.........Asterales
Family........Compositae (Asteraceae)
Genus........Rudbeckia

Identification:
³Leaves wider, the larger ones with the blade mostly less than 10 times as long as wide and more than 1 cm wide; Style appendages elongate, subulate; pappus none; herbage coarsely hirsute²
Cronquist, 1980.

General Information:
Rudbeckia hirta is a biennial that was originally from the western prairies. It usually has rays of golen or yellow petals with brown, conical centers. They can be found throughout most of the North American continent. It is found from the Eastern United States and even Canada, all the way to the Midwestern States of Colorado and Utah.
The black-eyed Susan grows 1 to 3 feet tall and its 2- to 4-inch-wide flowers bloom from mid- to late summer. The plant's coarse leaves grow on stiff stems cut flowers, but by the end of summer black-eyed Susans are often infested with aphids and mites.
The type specimen was named by Linnaeus and is held at The Museum, Bognor Regis in England.

Geography:

Rudbeckia hirta L.
AREA	STATUS	REFERENCES
North America: Continental United States; Canada	Yes	Radford, Ahles & Bell, 1968
Eastern North America: United States east of Mississippi; Ontario and eastern Canada	Yes	Radford, Ahles & Bell, 1968
Southeastern United States: AL AR DE DC FL GA KY MD NC SC TN VA WV	Yes	Cronquist, 1980
Southern Appalachian States: AL GA KY MD NC SC TN VA WV	Yes	Cronquist, 1980
Coastal Plain	frequent	Radford, Ahles & Bell, 1968;
Piedmont	frequent	Radford, Ahles & Bell, 1968
Blue Ridge Mountains	Marginal	Cronquist, 1980
Great Smoky Mountains National Park	?	-
Ridge and Valley	Yes	Jones & Coile, 1988
Cumberland Plateau	Yes	Jones & Coile, 1988
Central Arch	?	-
Georgia	Yes	Jones & Coile, 1988
Clarke County, Georgia	Yes	UGA Herbarium
Sams Farm	No	Pers. Ob.
Old Field	No	Pers. Ob.
Wetland	?	-
Woods	No	Pers. Ob.
1-Hectare Plot	No	Pers. Ob.

Natural History:
The Black-eyed Susan is a biennial that thrives in the high temps and direct sunlight. It is usually found in the meadows and pastures, as well as old fields and roadsides. They usually grow in undisturbed habitats and, even flourished in the Western Prairies in the early to mid 1900's. They however, are not as common as they were. The R. hirta. can also survive very well under cultivation and if cared for properly can flower a third year. Although they are found in Canada, they are not prevalent in many areas, such as Nova Scotia.

References:
1. Cronquist, Arthur. & Gleason, Henry. 1991. Manual of Vascular Plants of Norteastern United States and Adjacent Canada, Vol II. University of North Carolina Press. Chapel Hill, NC.