Mapping is tentative. In its broad sense, tenera is a widespread, variable, northern species of damp sites, but some more western plants have been segregated as var. echinoides (Fern.) Wieg. That taxon has recently been elevated to species status by Rothrock et al. (2009); 2n = 48-56 in typical tenera but 74-78 in echinoides. There are only scattered reports of tenera from Ky., several of which have been erroneous; however, FNA 23 did include Ky. in the range of var. tenera. A few colls. from Ky. appear to be intermediate between tenera and other taxa, and tenera is easily confused with normalis (especially), scoparia or other species (FNA 23); see Rothrock et al. (2009) for an updated key. C. echinoides is the most likely taxon of the tenera complex to occur in Ky. It is distinguished from normalis as follows: inflorescences arching or nodding (versus erect to somewhat bent), the lowest internodes mostly 10-24 mm long (versus 6-10 mm), the rachis usually thin and wiry (versus stiff); larger perigynia mostly 3.6-4.6 mm long (versus 3.1-3.8 mm), with L/W mostly 2.1-2.8 (versus 1.8-2.3); plants often forming large, spreading clumps of many culms (versus small, more erect clump of often <20 culms); habitat generally restricted to lowlands (versus uplands and lowlands). Typical tenera would be distinguished from both normalis and echinoides as follows: at least some sheaths minutely papillose near the collar (versus smooth), not prominently whitish-mottled (versus often so); perigynium beaks appressed to spreading-ascending in the spikes (versus spreading); beaks and shoulders of perigynia stramineous to reddish brown at maturity (versus greenish to greenish brown); pistillate scales mostly 0.8-1 times as long as the perigynia (versus 0.65-0.85), or sometimes longer and concealing beaks. Also, both echinoides and tenera have widest leaves mostly 1.5-3.5 mm wide (versus 2.5-6.5 mm in normalis).