This occurs mostly in east-central and midwestern states on damp fertile soils (W; Spaulding 2013b). It is a locally abundant weedy species, but apparently native. With abundant persistent long fleshy rhizomes, plants are difficult to eradicate from horticultural situations. Ecological comparisons with other semi-native herbaceous vining weeds in similar habitats would be interesting: Ipomaea spp. are mostly annuals; and Cynanchum laeve is a perennial with deeper roots plus more running laterals. The taxonomy and biogeography of the sepium group has remained uncertain, despite significant contributions by Brummitt (1980) and Mohlenbrock (1982). In Ky. distinction of fraterniflora from sepium needs to be reviewed further; apparent hybrids have been documented in Mo. (Y) and Pa. (NY). It is close to the Mediterranean C. silvatica (Kit.) Griseb., and has also been treated as C. silvatica ssp. fraterniflora (Mackenzie & Bush) Brummitt. Brummitt (1980) described related Chinese plants as ssp. orientalis. C. fraterniflora is distinguished from sepium by its saccate, largely overlapping, obtuse bracteoles (versus keeled, largely separate, acute to subobtuse); sharp-angled leaf lobes (versus sharp to blunt), the quadrangular sinus with nearly parallel sides (versus U or V shaped); and flowers consistently white (versus usually pink in eastern states) and 1-2 per axil (versus 1). The species produces white latex, a character that is documented in several other Convolvulaceae but poorly documented in eastern North America (Condon & Fineran 1989)