Rudbeckia fulgida sullivantii
Aster family (Asteraceae)
Description: This perennial wildflower is about 1½-2½' tall, branching occasionally. Low basal leaves are produced initially that are oval in shape and dentate along their margins; their bases are rounded to slightly cordate. Later, stems are produced that are light green with spreading white hairs. The alternate leaves are up to 5" long and 2½" across, becoming smaller and more narrow as they ascend the stems. Alternate leaves are ovate, broadly elliptic, or elliptic in shape, and dentate along their margins. The upper surface of each leaf is either hairless or sparsely covered with short appressed hairs; it is medium to dark green. The base of each alternate leaf tapers to a winged petiole; the base of the petiole is either sessile or clasps the stem.
The upper stems terminate in individual flowerheads spanning 2-3" across. Each flowerhead consists of 10-20 ray florets surrounding numerous tiny disk florets. The petal-like rays of the ray florets are yellow to orange-yellow with notched tips; they spread outward from the center of the flowerhead. The tiny disk florets are dark brownish purple and tubular-shaped. Each disk floret has 5 tiny lobes along its upper rim that are erect, rather than spreading outward. Each disk floret has a divided style with blunt tips. The blooming period occurs from mid-summer into the fall and lasts about 2 months. The mature achenes are oblongoid, 4-angled, and black; the upper end of each achene is truncate with a minute crown of tiny teeth (the pappus). Each achene is about 3 mm. in length or a little less. These achenes are light weight and can be blown about by the wind, but they usually don't stray far from the mother plant. The root system is fibrous and rhizomatous. In open disturbed areas, vegetative colonies are often formed from the rhizomes.
Cultivation: The preference is partial to full sun, moist to mesic conditions, and loamy or rocky soil that contains organic material. At a dry sunny site, there is a tendency for the leaves to wilt and the flowerheads may not develop properly. This coneflower requires cross-pollination with genetically distinct plants to produce viable seeds.
Range & Habitat: Sullivant's Coneflower is an uncommon native wildflower that is found primarily in scattered counties in the eastern half of Illinois (see Distribution Map). Habitats of this coneflower are rather variable: they include moist rocky woodlands, savannas and barrens, woodland openings and edges, moist meadows, limestone glades, moist rocky ledges, fens, hillside seeps, and swamps. Sullivant's Coneflower is typically found in high quality natural habitats, but it will temporarily colonize open disturbed areas.
Faunal Associations: Like other Rudbeckia spp., the showy flowerheads of Sullivant's Coneflower attract their fair share of pollinating insects; both nectar and pollen are available as floral rewards. Floral insect visitors include bees (leaf-cutting bees, Andrenid bees, Halictid bees), small butterflies and skippers, various flies (especially Syrphid flies and bee flies), and sometimes beetles (soldier beetles, weevils). Several moth caterpillars are known to feed on Rudbeckia spp.; they are usually found on the flowerheads, and include such species as Chlorochlamys chloroleuca (Blackberry Looper Moth), Eupithecia miserulata (Common Eupithecia), Synchlora aerata (Wavy-Lined Emerald), and Homoeosoma electellum (Sunflower Moth). Mammalian herbivores that browse on the foliage include deer, rabbits, groundhogs, cattle, and other farm animals.
Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois.
Comments: Orange Coneflower (Rudbeckia fulgida) is quite variable in appearance from one site to another. Consequently, this species has been a source of taxonomic problems that continues to this day. Some authorities classify Orange Coneflower as a single species consisting of several varieties, while others regard it as a complex of several closely-related species. Here, Sullivant's Coneflower is treated as a variety of Orange Coneflower. Sullivant's Coneflower can be distinguished from these other varieties by its larger flowerheads (typically 2-3" across) and the shape of its leaves. Other varieties of Rudbeckia fulgida that may be encountered in Illinois include: Rudbeckia fulgida fulgida (Orange Coneflower), which has more slender leaves and smaller flowerheads (1-2" across); Rudbeckia fulgida deamii (Deam's Coneflower), which has more hairy stems, smaller flowerheads (1-2" across), and larger upper leaves; and Rudbeckia fulgida speciosa (Showy Coneflower), which has slightly smaller flowerheads (1½-2½" across) and lower leaves that are more narrow and shallowly cleft. Among these different varieties, Sullivant's coneflower is the one that is most often cultivated in gardens. It is also possible to confuse Sullivant's Coneflower with the common Rudbeckia hirta (Black-Eyed Susan) in appearance, but it can be distinguished from the latter species as follows: 1) Sullivant's Coneflower has foliage that is less hairy, 2) its leaves have petioles that are conspicuously winged, 3) each of its achenes has a crown of tiny teeth, and 4) it is a perennial. In contrast, Black-Eyed Susan has more hairy foliage, its petioles lack conspicuous wings, its achenes are truncate at the apex, and it is usually annual or biennial in habit.