Heliopsis helianthoides is a species of flowering plant in the family Asteraceae, known by the common names rough oxeye, smooth oxeye and false sunflower. It is native to eastern and central North America from Saskatchewan east to Newfoundland and south as far as Texas, New Mexico, and Georgia.

Heliopsis helianthoides is a rhizomatous herbaceous perennial growing 40–150 cm (16–59 in) tall. The toothed leaf blades are oval to triangular or lance-shaped and may be smooth or hairy or rough in texture. The flowers are produced from midsummer to early autumn (fall). The inflorescence contains one to many composite flowerheads. Each head contains yellow ray florets which are generally 2–4 cm (3⁄4–1+1⁄2 in) long. The rays are fertile, having a small forked pistil at the base; this distinguishes them from true sunflowers. At the center are many yellow to brownish disc florets. The fruit is an achene about 5 mm (0.20 in) long.

In the wild, H. helianthoides may be found in wooded areas and tallgrass prairie, and sometimes along roadsides.

It is a popular garden plant for moist, fertile soil in full sun. Plants grow stiff and tall, so may require staking. Several cultivars are available with flowers of varying colors and shades. These include 'Summer Sun', 'Golden Plume', and 'Prairie Sunset'. The following cultivars of H. helianthoides var. scabra ("rough") have gained the Royal Horticultural Society's Award of Garden Merit:

• 'Benzinggold'
• 'Light of Loddon'
• 'Loraine Sunshine'='Helhan'
• 'Sonnenglut'
• 'Spitzentänzerin'
• 'Waterperry Gold'

The Botanical Latin species name helianthoides means “resembling sunflowers”.

...