Mapping is tentative, pending revision of the genus. Some colls. of Heliopsis from riparian woods and edges on the Coastal Plain in Ky. (CALL, FULT, GRAV, TRIG) suggest at least transitions to gracilis. This is a relatively distinct southern taxon that has generally smaller plant dimensions than helianthoides and may deserve species status (FNA 21, Thomas 2017); further investigation is needed. It reportedly differs from helianthoides as follows (FNA 21, W): aerial stems 1-2+ (versus 1-10+), 3-8 dm tall (versus 4-15 dm), from creeping rhizomes 4-10+ cm × 1-2 mm (versus 0-4 cm x 2-6 mm), with rhizome internodes ca. 20+ mm long (versus 2-10 mm); leaf blades 4-8 × 1.5-3 cm (versus 6-15 × 2.5-12 cm); heads 1-5 (versus 1-15+); rays 6-13 (versus 9-18), 1-2.4 cm long (versus 1.5-4 cm). H. gracilis is previously known mostly from the West and East Gulf Coastal Plain as far north as Miss. and Ark., plus a few sites in S.Car. (K, W, FNA 21; Campbell & Seymour 2018). It has also been identified recently in Mo. (Thomas 2017).