From the August 2007 Conservationist
By Barbara Nuffer
Black-eyed Susan is a favorite summer-blooming native wildflower that flourishes in New York State's fields and meadows. It can be found growing in all areas of the United States, except the Southwest.
There are approximately twenty five native North American Rudbeckia species, with eight native species in the Northeast. Rudbeckia hirta was originally native to the dry prairies of the Midwest. One feature that contributes to the drought tolerant nature of this plant include a root system that is adapted to maximize water absorption. Another is that the hairy leaves and stems of the plant are designed to minimize water loss and the species name Hirta, or hirt in Latin, means hairy. The genus name is in honor of Swedish botanist, Olaus Rudbeck (1660-1740).
Black-eyed Susan flowers are composite flowers, which are found in all members of the Aster Family. A composite "flower" is actually made up of two types of small flowers called florets, the outer "Ray" flowers and central "Disk" flowers. The three inch wide Black-eyed Susan flower head has an outside ring of approximately ten to fourteen sterile ray florets. Each ray floret has one yellow petal and surrounds the central disk. In the center of the Black-eyed Susan there are two to three hundred fertile dark brown disk florets that each produce a seed.
As a biennial, the plant develops a rosette of leaves in the first year and blooms in the second year, with a one to three foot flowering stem. Most plants will only live for two years, but an occasional one may live for an additional year or two.
Many insects feed on the nectar and yellow pollen of this plant, including several different species of bees, flies, and butterflies. Caterpillars will eat the leaves and finches enjoy the seeds. Interestingly, the ultraviolet vision range of bees sees the yellow petals as 3 concentric bull's eye rings surrounding the brown center. This pattern serves as a "guide" to lead the bees to the pollen and nectar in the central disk florets.
Native Americans used the root of this plant to make a tea for the treatment of colds and parasitic worms in children. It was also used as a skin wash for sores and snake bites, and drops were made from the root to treat earaches. They used the yellow disk florets to create a dye to color rushes to be woven into mats.. A cultivar of Rudbeckia hirta, Gloriosa Daisy, is a three to four foot tall plant. The flowers of the variety "Indian Summer" range in color from yellow through mahogany. Although the original plants will last only a season or two, they will self-seed readily to form new plants.
You can also enjoy the Black-eyed Susan in your garden with a close relative, Rudbeckia fulgida "Goldsturm" It was named the 1999 "Perennial Plant of the Year". If you remove the spent flowers it will bloom continuously from July through October. "Goldsturm" is a long-lived perennial that forms a large clump and is easily divided in spring.
Black-eyed Susans, both in the garden and in the meadow, provide bright golden-yellow flowers into the fall. The flowers of this widespread wildflower adds another layer of beauty to the reds and yellows of the colorful fall landscape found in the woods across New York State.