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Juncus

See list of 38 species in this genus

References: Hämet-Ahti (1980), Brooks and Clemants (2000).

  • 1a. Involucral bract solitary, of similar cross-sectional shape as the stem and appearing 
to be a continuation of it, therefore, the inflorescence appearing to emerge from the side 
of the stem (i.e., pseudolateral) [Figs. 146,150]; leaves bladeless, consisting of sheaths only
    • 2a. Stems cespitose; flowers with 3 stamens (or with 6 stamens in the rare introduction 
 J. inflexus)
      • 3a. Capsules red-brown to dark brown, (2.5–) 3–4 mm long; stamens numbering 
6 per flower, with filaments 0.8–1.5 mm long and anthers 0.8–1 mm long; stems prominently glaucous in life
      • 3b. Capsules tan to green-tan or brown, 1.5–3.2 mm long; stamens numbering 3 per flower, with filaments 0.5–0.8 mm long and anthers 0.5–0.8 mm long; stems green
        • 4a. Apical portion of stem relatively lustrous, smooth or nearly so below the inflorescence, the (25–) 30–60 longitudinal striations inconspicuous until drying 
 [Fig. 146]; ridges of dried stems capped with dull, low cells
        • 4b. Apical portion of stem relatively dull, evidently ridged below the inflorescence with mostly 10–30 longitudinal grooves [Fig. 150]; ridges of dried stems capped with lustrous, papillose cells
          • 5a. Involucral bract swollen at the base of the inflorescence, sometimes somewhat reflexed in fruit; leaf sheaths with red-brown bases, the upper ones 15–23 cm long; inflorescence compact, mostly 10–25 mm in diameter; stems with 12–30 longitudinal ridges; tepals spreading from the base in fruit
          • 5b. Involucral bract not swollen, erect in fruit; leaf sheaths with dark red-brown to purple-black bases, the upper ones 5–12 cm long; inflorescence relatively open, mostly 15–80 mm in diameter; stems with 10–20 longitudinal ridges [Fig. 150]; tepals ascending or appressed to the capsule in fruit
    • 2b. Stems produced singly or a few together from an elongate rhizome; flowers with 
6 stamens
  • 1b. Involucral bracts usually 2 or more, differentiated from the stem in some manner, the inflorescence appearing terminal [Fig. 151]; leaves with blades

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 Show photos of:   Each photo represents one species in this genus.