Juncus effusus L.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Densely cespitose; stems to 1+ m, smooth or with 30–60 very low, inconspicuous ridges, the epidermal cells over the ridges not enlarged; basal sheaths to 2 dm, bladeless, mostly reddish-brown; invol lf (10–)15–25(–35) cm, appearing like a continuation of the stem; infl apparently lateral, many-fld, usually open, the longest branches (3–)4–10 cm; fls prophyllate; tep 2–2.5(–3) mm, stramineous, broadly lanceolate, acute, the outer commonly a bit longer than the inner; anthers 3; fr trilocular, slightly shorter to slightly longer than the tep, mostly obtuse to truncate, seldom J. griscomi) mucronate; 2n=40, 42. Open marshes and wet meadows; nearly cosmop., and throughout our range. Our common native plant, throughout e. U.S. and se. Can., is var. solutus Fernald & Wiegand, with rigid tep closely investing the fr. The European var. effusus, with soft tep ± spreading from the base, is locally intr. from Nf. to Me. and inland to Mich. and Minn. (Var. compactus, a form with compact infl)