This northeastern taxon of base-rich wetlands appears closely related to pseudoptera; 2n = 38 probably in both taxa (FNA 23). The best diagnostic character of elliptica is the (4) 6-8 (10) angles in stem cross-sections; other taxa in the tenuis group have 4 (5) angles. There are almost no definitive records from Ky., but a skimpy coll. from the Backbone Swamp in FRAN (EK) is tentatively included here. Also, a few colls. appear transitional from elliptica to compressa (LEWI at KNK, R.F.C. Naczi #3811), or to tenuis (ROWA at MDKY & KNK, L. Meade #564; mapped as elliptica by BT). E. acuminata (Muhl.) Nees is a synonym of elliptica, but it has been applied in some cases to plants now known as E. bifida (M).