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Northern Prairie Wildlife Research Center

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Native Wildflowers of the North Dakota Grasslands

JPG -- species photo

Black-eyed Susan (Rudbeckia hirta)

As we approach mid-July, black-eyed susan will begin to flower on the North Dakota prairie. Originally a plains and prairie dweller, the species rapidly spread eastward as European man cleared the primeval forest. Today, this somewhat weedy species ranges from Newfoundland to Florida west to British Columbia and Mexico, at elevations under 9,000 ft.

Black-eyed susan is a rough, hairy biennial that flowers at the end of the second growing season. Plants are up to two feet tall, with narrow, toothed leaves that are spaced alternately on the stem. Flower heads are about two inches across. The short disc flowers in the center of the head are dark purplish-black, whereas the long outside ray flowers are bright yellow. Fruits are smooth, four-angled achenes.

Black-eyed susan seems little affected by grazing. Look for it in slightly moist soil such as is found at the bases of hills, along coulee bottoms, or in the low prairie just shoreward of wetlands.

This plant is a member of the sunflower family (Asteraceae) which contains over 15,000 species worldwide, and about 200 species in North Dakota. The renowned Swedish naturalist Carl von Linne (Linnaeus) dedicated the genus to two of his professorial predecessors at the University of Uppsala, the father (1630-1702) and son (1660-1740) Olaf Rudbeck. Hirta means "rough hairy" in botanical Latin. Linnaeus was also the first to describe this particular species in his monumental Species Plantarum of 1753. Modern botanists consider this book to contain the first scientifically acceptable descriptions of plants.

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Return to Asteraceae (The Aster Family)
Next Species -- Gray Ragwort (Senecio canus)

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