Heliopsis, the False Sunflower, differs from the true Sunflowers (Helianthus) chiefly in having both the ray and disk flowers fertile, that is, capable of producing seed. In the true Sunflowers, the ray flowers are neutral. The Oxeye or False Sunflower is 3 to 5 feet high. Leaves opposite, petioled, ovate to lanceolate, thin, rather evenly toothed on the margins, 3 to 6 inches long and 1 to 21/2 inches wide. Heads of flowers yellow, borne on long peduncles; bracts of the involucres oblong or linear-oblong, the outer ones usually longer than the inner.
In low or moist soil, usually in open places and along streams, Ontario to New York, west to Illinois and North Dakota, south to Florida and Tennessee. Flowering from July to September. Closely resembling the Pale-leaved Wood Sunflower.
Memoir 15 N. Y. State Museum
Oxeye; false sunflower Heliopsis helianthoides