Juncus effusus Linnaeus ssp. solutus (Fernald & Wiegand) Hämet-Ahti. Subgenus: Agathryon. Section: Juncotypus. Phen: Jun-Sep. Hab: Moist soil, marshes, margin of streams, ponds, lakes and swamps, low meadows. Dist: NL (Newfoundland) to MN, south to s. FL and Mexico.
ID notes:Of section Genuini (species with lateral inflorescence), this species is easily the most common. Distinguished by the easily compressible stems (giving the common name “Soft Rush”, and very different than the tough, wiry culms of another common and widespread species, Juncus coriaceus), fine stem ridges that are not pronounced, and tepals that +/- equal the tepals.
Origin/Endemic status: Native
Other Comments: Ssp. effusus is European, and also occurs (apparently introduced) in the ne. United States.
Synonymy: = K3, K4, Mo1, NE, NY, Tn, WH3, Hämet-Ahti (1980), Kirschner (2002b), Kirschner (2002c), Zika (2003), Zika (2013); = Juncus effusus L. var. solutus Fernald & Wiegand – C, Il, NcTx, Pa, Tx; > Juncus conglomeratus L., misapplied; < Juncus effusus L. – Ar, ETx1, FNA22, GrPl, GW1, Meso6, Mi, RAB, S, Va, W; > Juncus effusus L. var. compactus – G, misapplied; > Juncus effusus L. var. conglomeratus (L.) Engelm. – K1, misapplied; > Juncus effusus L. var. solutus Fernald & Wiegand – F, K1; >< Juncus effusus L. var. solutus Fernald & Wiegand – G; > Juncus griscomi – F; > Juncus griscomii Fernald – G