Typical jacea may be unknown in Ky. The jacea/nigra complex has defied stable taxonomic interpretation, with 3-4 or more species sometimes recognized in North America (FNA 19, W). Each of this segregates has reported diploids and tetraploids; also hybridization is suggested. All records of jacea from Ky. may be referable to C. X moncktonii; see notes under nigra. The whole complex is widespread across western and northern states, but it is uncommon to absent in most southeastern states.