cutleaf coneflower (Rudbeckia laciniata var. laciniata)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COMMON NAMES:

cutleaf coneflower

cut-leaf coneflower

goldenglow

wild goldenglow

green-headed coneflower

greenheaded coneflower

tall coneflower

thimbleweed

SCIENTIFIC SYNONYMS: There are no scientific synonyms for Rud-

beckia laciniata.

CONFIRMATION STATUS: Pending confirmation.

TAXONOMY: The currently accepted scientific name for cutleaf cone-

flower is Rudbeckia laciniata L. There are five native varieties of Rudbeck-

ia laciniata occuring in North America, three recorded in Virginia: 1) var-

iety digitata (P. Mill.) Fiori (coastal plain cutleaf coneflower), 2) variety

humilis Gray (southeastern cutleaf coneflower), and 3) variety lainiata

(cutleaf coneflower). Variety digitata is found in southeastern Virginia

while variety humilis is found in southwestern Virginia. Variety laciniata

is found throughout Virginia is the presumed species in Sky Meadows

State Park.

NATIVE STATUS: Native, United States and Canada.

GENERAL BOTANICAL CHARACTERISTICS:

 

Habit: This native perennial plant is 3-8' tall; it branches occasionally in

the upper half. The stems are light green, terete, usually glabrous, and

sometimes glaucous.

 

Leaves: The alternate leaves are up to 12" long and 12" across, becoming gradually smaller as they ascend the stems. These leaves spread outward

from their stems on narrowly winged petioles and they have a tendency to

droop. The lower to middle leaves have 3-7 large lobes and smooth to

coarsely dentate margins. The lobes of these leaves are elliptic to ovate in

shape; the terminal lobes of some leaves are subdivided into 2 smaller

lobes. Sometimes the lower leaves are pinnate with a pair of basal leaflets

and a lobed terminal leaflet. The uppermost leaves on the flowering stalks

are much smaller in size and lanceolate to ovate in shape; they lack lobes.

The upper leaf surface is dark green and hairless to sparingly short-hairy,

while the lower leaf surface is pale-medium green and glabrous to sparing-

ly hairy.

 

Flowers: The upper stems terminate in either individual or cyme-like clust-

ers of flowerheads on stalks 2" or more in length. Each flowerhead spans

about 2-3" across; it has a daisy-like structure consisting of a globoid cen-

tral cone that is surrounded by 6-12 ray florets. The central cone is light

green while immature, but it later becomes yellow and resembles a pin-

cushion to some extent because of the corollas of its tubular disk florets.

The petaloid rays surrounding the central cone are yellow, oblong in shape,

and drooping. The base of each flowerhead is defined by 8-15 floral bracts (phyllaries); these bracts are light green, oblong-ovate in shape, and hair-

less to hairy.

 

Fruit/Seeds: Each disk floret is replaced by an oblongoid achene (3-4.5

mm. in length) that has a crown of tiny blunt teeth at its apex.

 

Roots: The root system is fibrous and rhizomatous. Clonal colonies of

plants are often formed from the long rhizomes.

REGENERATION PROCESS: Cutleaf coneflower propogates itself by

reseeding and vegetative rhizome spread.

 

HABITAT TYPES: Habitats include open bottomland forests, moist meadows in wooded areas, woodland borders, moist thickets, sloughs in partially shaded areas, low areas along rivers, partially shaded river banks, calcareous seeps, margins of poorly drained fields, and pastures. Occasionally, this species is grown in flower gardens. It prefers partially shaded areas that are poorly drained and may be prone to occasional flooding during the spring.

SITE CHARACTERISTICS: The preference is partial sun, moist conditions, and fertile loam or silt-loam. At a site that is too sunny and dry, the leaves may droop excessively and wither away, otherwise this plant is easy to cultivate. In some areas, it may spread aggressively by means of its rhizomes.

SEASONAL DEVELOPMENT:The blooming period occurs from mid-summer to early fall and lasts about 1-2 months.

GENERAL DISTRIBUTION: Cutleaf cornflower is found throughout most of

the contintental United States (excepting California, Oregon, Nevada, and Utah),

all the eastern Canadian provinces (except Newfoundland), and west to Manitoba.

SKY MEADOWS DISTRIBUTION: To be determined.

IMPORTANCE AND USES: The nectar and pollen of the flowerheads attract many kinds of insects, including long-tongued bees, short-tongued bees, predatory wasps, butterflies, skippers, moths, and various kinds of flies. Insects that feed destructively on the cutleaf coneflower include the leaf beetle Sumitrosis inequalis, Uroleucon rudbeckiae (golden glow aphid), larvae of the fruit fly Strauzia intermedia, leaf-mining larvae of the moth Marmara auratella, and larvae of the butterfly, Chlosyne nycteis (silvery checkerspot). Other insects that feed on this and other coneflowers (Rudbeckia spp.) include the larvae of gall flies, larvae of the sawfly Macrophya simillima, and larvae of some Tortricid moths. Larvae of such moths as Synchlora aerata (wavy-lined emerald) and Eupithecia miserulata (common pug) feed on the florets. A bird, the common goldfinch, eats the seeds to a limited extent. The foliage of cutleaf coneflower may be somewhat poisonous to some mammalian herbivores.

 

 

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