This widespread eastern perennial is often confused with subglabrata, which tends to occur on damper, richer soil. Pubescence patterns are distinct (F, W, Y): stems, pedicels and calices (especially the nerves) have thin to dense minute (0.1-0.5 mm) retrorse hairs plus usually also longer spreading hairs to 2 mm (versus glabrous to sparse with minute antrorse hairs but without longer hairs). Also, principle leaf blades are 3-6 cm long (versus 5-8 cm); filaments are as wide or wider than the anthers (versus half as wide); spots at base of the corolla are prominent (versus inconspicuous to absent). P. virginiana usually flowers earlier in Ky. (Jun-Jul versus Jul-Aug). P. virginiana was apparently misnamed P. pensylvanica L. in early literature from Ky. (M).