Typical pruinosa is a widespread variable species in northeastern states, but it is rare to absent on the southeastern Coastal Plain (F, W, Lance 2014). Treatment of intraspecific variation remains unresolved, probably with diploids, triploids and tetraploids (FNA 9). The mapped records here include C. dissona Sarg. (with only 10 stamens), C. mackenzii Sarg. (with broader leaf bases), C. rugosa Ashe (with even broader leaves) and C. compacta Sarg. (a possible transition to series Silvicolae), which have not been clearly distinguished in Ky. in most previous treatments (Cr, M). C. locuples Sarg., a probable hybrid with mollis, has been reported (F; see also C. platycarpa Sarg. in D and St). C. pruniosa var. virella (Ashe) Kruschke has been reported from BOYD (Horsey #1583 at GH) and perhaps POWE (NP); this somewehat pubescent variant suggests a transition to mollis. There may also be hybrids with series Punctatae. C. gattingeri has been combined with pruinosa in some treatments; but see notes under that name. Both species have glabrous reddish-brown fresh twigs, with thorns becoming deep purplish to black; distinction of series Pruinoseae from series Molles can often use these characters (see below).