In Ky. this perennial is probably all var. major Torr. & Gray, which has not been distinguished from typical filipes in recent treatments but deserves further attention (Munz 1938, 1965; F). Var. major has larger petals (ca. 6 mm long versus 4-5 mm), larger calyx segments (8-10 mm long versus 5-7 mm), and larger leaves (mostly 3-7 cm long versus 2-5 cm). It occurs mostly in the Interior Low Plateaus (except the Bluegrass region) and perhaps other calcareous localities in southeastern states. In Ky. it is restricted to calcareous glades or nearby, whereas the habitat for typical filipes further south is "sandy pine-barrens" (F) or "sandy fields, disturbed areas and clearings" (W). Reports from Ky. of the southern biennial, G. angustifolia Michx., have probably been based on filipes (M). There has also been confusion with filiformis ("longiflora") in southeastern states; see notes under that name. Identifications can be unreliable when based simply on stipe length, which is usually (0.5) 1.5-3 (4) mm in filipes, versus usually 0-1 mm in other native eastern species, but often up to ca. 2 mm in some filiformis and angustifolia. The slender "clavate-obovoid" shape of the fruit in filipes is also important to note; in other eastern species, the shape is fusiform to ovoid and usually less tapered to the base.