We find these charming yellow violets on moist wooded hillsides; these grew near the Trillium Trail in Fox Chapel.
Gray lists this as Viola scabriuscula; others as V. pubescens var. scabriuscula or V. eriocarpa. From Gray’s Manual of Botany: V. scabriuscula Schwein. (SMOOTH YELLOW V.) Similar to the preceding [V. pubescens], with which it intergrades ; the more pronounced forms have commonly 2-4 stems and 1-3 radical leaves from one rootstock, the stems shorter and more leafy, the leaves smaller and sparingly pubescent to glabrate, the time of flowering earlier ; flowers, capsules, and seeds as in the preceding [petals purple-veined, the lateral bearded ; sepals narrowly lanceolate, acute ; apetalous flowers abundant in summer on short peduncles ; capsules ovoid, glabrous or woolly ; seeds light brown, large, nearly 3 mm. long]. Moist thickets, often in heavy soil, e. Que. to L. Winnipeg, and southw.