This is a widespread diploid (2n =14, 18) on base-rich soils across temperate North America, but less common on the southeastern Coastal Plain (FNA 3, K, W). In addition to rocky woods, especially below limestone cliffs, typical habitats include dusty ground below eaves of buildings and similar bared soils. Distinct variants of pensylvanica are not currently recognized. A few depauperate plants have been misidentified as P. praetermissia Hinton or the often confused P. floridana Nutt., which both occur further south on the Coastal Plain. Colls. of B from clifflines that she reported as floridana have been redetermined as pensylvanica (M). However, Braun #2269 from Cox Bend in WAYN (US) and her coll from Hocking Co., Ohio (US, 29 Sep 1943), do have unusually small leaves, as does Medley #7142 from Tight Hollow in WOLF (APSC). More recently, two other colls. of especially diminutive plants (ca. 5-15 cm tall) from similar habitats have appeared close to floridana: (1) D. Dourson & D. Taylor (BEREA, 2 Jul 1990), from MENI in "west-facing sandstone rockhouse along Indian Cr."; (2) P. Adanick, J. Campbell & D. Dourson (APSC, 12 Jul 2020; plus plants then cultivated), from POWE below a sandstone cliff near Rogers Chapel. These MENI and POWE colls. have a few mature seeds, but more material is desirable for description. In contrast to floridana, the seeds of these plants are relatively dark olive-brown (versus light brown); their size is similar (ca. 0.8 x 0.6 mm) but they lack a distinctly flared base to the stipe. Leaf blades are orbicular to deltate to broadly ovate (somewhat like floridana), but they are mostly 1-3.5 x 1-3 mm (MENI) or 2-9 x 2-6 mm (POWE), which are much smaller than typical floridana (7-27 x 5-17 mm) and even smaller than typical pensylvanica (10-70 x 4-30 mm; Sm, F, FNA 3, Y). Leaf size remained small in cultivated plants during 2020. These leaves do not have the basal divergence of main lateral veins that is considered typical of floridana (W), although the distinctly smaller proximal leaves of that species do not always exhibit basal divergence. It is possible that these colls. represent a distinct variant of pensylvanca with unusually small dimensions, especially in leaves (and perhaps with darker seed color on average). Alternatively, diminutive size could be caused by the unusual dry infertile soils under these clifflines.