Typical pungens is a rhizomatous plants that has been reported widely from marshy wetlands of South and North America, but it may be relatively uncommon in warmer regions of southeastern states (Cr, FNA 23, K, W). Variation needs further assessment; 2n = 74-78. It is likely that the western segregate, var. longispicatus (Britt.) S.G. Sm., also occurs in Ky. but there are no records so far. The name Scirpus americanus Pers. was misapplied to pungens in some older treatments (e.g. F). True americanus (= Scirpus olneyi Gray) is a closely related southern species of alkaline or saline marshes that is unknown in Ky. (FNA 23).