Asteraceae/Compositae (ASTER/COMPOSITE FAMILY)
This perennial wildflower is 2½-6′ tall with a central stem that becomes branched where the flowerheads occur. This stem is light green to dark purple, slender, terete (round in cross-section), glabrous to sparsely covered with short stiff hairs, and sometimes glaucous. Upper secondary stems have similar characteristics. Pairs of widely spreading opposite leaves occur along the central stem and any secondary stems; each pair of leaves rotates 90° from the pair of leaves below. Leaf blades are 2-6″ long and ½-2″ across; they are lanceolate-oblong to ovate-oblong in shape, and either toothless or with widely spaced teeth along their short-ciliate margins. The base of each leaf blade is rounded-truncate, while its tip is long and gradually tapering. The upper surface of the leaf blades is yellowish green to medium green and sparsely to moderately covered with short stiff hairs, while the pale lower surface is short-pubescent, especially along the major veins. Three prominent veins join together at the base of each leaf blade. The leaves are sessile or they have short ascending petioles (about 1/8″ long).The Woodland Sunflower is easily identified by its sessile, or nearly sessile, opposite leaves. Other sunflowers (Helianthus spp.) have longer petioles. Its stems are usually hairless or mostly hairless, unlike Helianthus hirsutus (Hairy Sunflower) and some other species in this genus. Compared to some narrow-leaved sunflowers that occur in prairies, the leaf bases of Woodland Sunflower are more broad and nearly truncate.
The butterfly is a Pearl Cresent (Phyciodes tharos)