Also called rough sunflower and ten-petal sunflower, this herbaceous perennial is native to the woodlands and forests of Eastern and Central US. It is a member of the daisy family, Asteraceae, that also includes daisy, yarrow, and lettuce. Plants have a rhizomatous root system and smooth slender stems that are 2-7′ tall and branched at the top. The ovate to lanceolate dark green leaves are 3-7″ long and have coarsely toothed margins. Flowerheads are 1-3″ across and appear from mid summer into fall. Each flowerhead consists of 7-12 light yellow ray florets surrounding a center of numerous yellow disc florets. The flowers are attractive to butterflies and bees and the seeds are attractive to birds. Thin leaf sunflower is a good choice for a wildlife, butterfly, native plant, wildflower, or meadow garden. The genus name, Helianthus, comes from the Greek words helios, meaning sun, and anthos meaning flower and may refer to the resemblance of the flowerhead to the sun. The specific epithet, decapetalus, comes from the Greek word deka meaning 10 and the modern Latin word petalus meaning petal, referring to the ray florets of the flowerheads.
Type: Herbaceous perennial
Bloom: Flowerheads with yellow ray and disc flowers from mid summer to fall
Size: 2-7′ H x 4′ W
Light: Full sun to partial shade
Soil: Average, medium moist, well-drained
Hardiness: Zones 4-9
Care: Low maintenance
Pests and Diseases: Downy mildew
Propagation: Seed, division
Companion Plants: Red tinged grass, golden rod, asters, Joe Pye weed
Outstanding Selections: ‘Capenoch Star’ (clear yellow flowers; floriforous)
Photo Credit: H. Zell, Wikipedia
Karen Meyers