Juncus fascinatus (Juncaceae), a new combination in Juncus sect. Ozophyllum and notes on morphologically similar species

Research of the morphologic variation within Juncus (Juncaceae) sect. Ozophyllum has revealed the need for a new combination, Juncus fascinatus. Univariate and multivariate statistical analyses show that J. fascinatus is morphologically distinct from J. validus. Juncus fascinatus is described, illustrated, and compared to the superficially similar species J. paludosus, J. polycephalos, and J. validus. Juncus fascinatus is endemic to 25 counties in north-central and southeastern Texas whereas J. validus is more widespread and weedy. Juncus fascinatus is distinguished from J. validus by a united capsule apex at dehiscence, capsule length, inner and outer tepal length, length by which the capsule exceeds the tepals, and inflorescence length and width. Juncus validus is ecologically distinct from J. fascinatus and has shown a rapid range expansion throughout the southeastern United States and into the Mid-Atlantic. Juncus validus is most likely non-native west of the Mississippi River. The morphologically similar J. paludosus is reported from Alabama, Georgia, Louisiana, and South Carolina for the first time.  Juncus polycephalos is reported from Kansas.