Sedge

Some authors included various other members of section Acrocystis as varieties under C. nigromarginata. These include C. nigromarginata var. elliptica (Boott) Gleason = C. peckii; C. nigromarginata var. muhlenbergii (Gray) Gleason = C. albicans var. albicans; C. nigromarginata var. minor (Boott) Gleason = C. albicans var. emmonsii; and C. nigromarginata var. floridana (Schweinitz) K?kenthal (which only occurs south of New York) (Gleason 1952, Crins and Rettig 2002). Rettig (1988, 1990) and Rettig and Giannasi (1990) have placed C. nigromarginata in the C. nigromarginata complex comprised of C. nigromarginata, C. floridana, C. albicans var. albicans, C. albicans var. emmonsii, C. albicans var. australis, and C. peckii. In these studies the researchers found C. nigromarginata to be distinct at the species level. Roalson and Friar (2004) found that the C. nigromarginata complex is not monophyletic. Possibilities for the non-monophyly of this complex include cryptic species, hybridization, and gene paralogs.