This southeastern species is most common in Va., N.C. and S.C., especially on soils which are relatively base-rich for that region (F, W). In Ky. occidentalis does not overlap much in range with the more southwestern species, helianthoides and virginica. This pattern appears partly related to substrate, with occidentalis concentrated on more acid soils, but historical factors may also be involved. V. occidentalis is often especially abundant in old rough pastures, where cattle avoid the plants. Reported extensions or disjunctions of occidentalis to the west of Ky., Tenn. and Ala. are largely anomalous and deserve further verification (Cr, FNA 21, K, PL). The species is not verified in Ark. or Mo. (Y). It has apparently been confused with alternifolia or helianthoides, leading to erroneous reporting of ranges. Identifications have often relied too much on the tendency of occidentalis to have largely opposite leaves, and the other species to have largely alternate leaves. A better key is needed, emphasizing differences in head dimensions, components and numbers. V. occidentalis has the smallest heads of yellow-flowered species in North America, with involucres only 3-5 mm wide, and rays numbering only (0) 1-3 (5). Verbesina is a large diverse genus of warmer American regions. Several sections have been established (W), in some cases recognized as separate genera (Sm, Gl).