Plants of the Eloise Butler Wildflower Garden

Green-headed Coneflower is a native erect perennial forb growing on stems that can reach 7+ feet in height, are smooth and branch near the top into multiple flower heads. The text here treats var. laciniata.

The leaves vary in shape and size with the lower leaves being palmately divided into 5 to 9 lobes with serrate irregular edges. Mid-stem leaves will have fewer lobes than basal leaves and then graduating up the stem to 3 lobed or un-lobed and then to bracts within the floral array. Leaf petioles have a shallow groove. Leaf surfaces are usually smooth or with only sparse hair.

The floral array consists of branched clusters of several to many heads, each head on a long stalk and the cluster itself on a long stalk held above the leaves.

The flower heads are composite with both ray and disc florets. Ray florets can make the head 2 1/2 to 4 inches wide. There are 8 to 12 yellow drooping rays which are sterile. These are smooth on the upper surface, slightly hairy on the underside. The fertile florets of the central disc number 150 to 300+, have a tubular yellow to yellowish-green corolla (turning dark brown at maturity), with five yellow lobes at the tip and 5 stamens with purple anthers. The style is yellow, split into two tips, and is tightly surrounded by the stamens. Style and stamens are exserted from the corolla throat when receptive. The corolla lobes do not spread outward when in flower. Around the outside of the flower head are several series of phyllaries (floral bracts) that number 8 to 15, are of unequal length, pointed, and some stick out between the yellow rays. These can have some fine hair, particularly on the margins. The central disc is domed, slightly flattened at first, then more hemispherical when all the florets have opened; opening from the perimeter first then toward the center.

Seed: Flowers mature to a dry seed (a cypsela) 4.2 to 6 mm long, without fluffy pappus (but with short bristles), conical in shape, ribbed, with crown-like projections at the larger end. Seed dispersion is by wind shaking the stem. Seeds require 30 days of cold stratification for germination.

Varieties: Five are recognized: One has an ovoid shaped receptacle - var. ampla. Four have a globose to hemispheric receptacle - var. heterophylla where the leaves are not lobed; var. digitata where the lower leaves have 3 to 5 lobes but are not pinnatifid (fern like); var. bipinnata where the lower stem leaves are 2-pinnatifid and cypselae are 3.5 to 4 mm long; and finally var. laciniata where the lower stem leaves are pinnatifid only and the cypselae are 4.2 to 6 mm long. This is the variety native to Minnesota.

Habitat: Green-headed Coneflower grows best in full sun and somewhat moist soil. It also grows well in partial shade in moist soils. It has a rhizomatous and fibrous root system, but does not spread agressively.

Names: The genus Rudbeckia, is named after the Swedish father and son, - Olaf. J. Rudbeck the elder (1630-1702) and Olaf O. Rudbeck (the younger 1660-1740), who were professors of botany at Uppsala. Carl Linnaeus was the favorite pupil of the younger Rudbeck. The species name laciniata, is from the Latin meaning 'slashed' or 'torn' which is the look of the leaves. The author name for the plant classification, 'L.', refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.

Comparisons: The flower form is similar to the Gray-headed Coneflower, Ratibida pinnata, but there the leaf is composed of leaflets, not just palmately divided and the floral array has only one or several heads, not a branched cluster. A much shorter plant is the Long-headed Coneflower, Ratibida columnifera, (also called Prairie Coneflower) which, as the name implies, has a much taller disc cone. See notes below on the commercial "Goldenglow".