The Jepson Manual: Higher Plants of California

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  • Up-to-date information about California vascular plants is available from the Jepson eFlora.

Names are linked to treatments from the Manual


Key to ACHNATHERUM

N.B.: couplets are linked, e.g., 1. is linked to 1'.

  1. Basal segment of awn hairy, some hairs > 1 mm; callus sharp
 
    2. Lowest hairs on awn > upper lemma hairs
 
      3. Awn with 1 bend; uppermost ligule 0.3–1 mm, long ciliate
A. speciosum
      3' Awn with 2 bends; uppermost ligule 2–7 mm, glabrous
 
        4. Inflorescence 15–30 cm; uppermost ligule 2–4 mm, opaque
A. latiglume
        4' Inflorescence 7–13 cm; uppermost ligule 3–7 mm, translucent
A. thurberianum
    2' Lowest hairs on awn < upper lemma hairs
 
      5. Palea 2/3–3/4 lemma length
A. nevadense
      5' Palea 1/3–1/2 lemma length
A. occidentale
        6. All awn segments hairy
subsp. occidentale
        6' Lower awn segments hairy, upper glabrous
 
          7. Hairs of lemma tip = hairs at awn base
subsp. californicum
          7' Hairs of lemma tip > hairs at awn base
subsp. pubescens
  1' Basal segment of awn scabrous; callus sharp or blunt
 
    8. Hairs of lemma tip 2–7 mm
 
      9. Awn 3–11 mm, straight, readily deciduous
 
        10. Inflorescence open, branches and pedicels widely spreading
A. hymenoides
        10' Inflorescence dense, branches and pedicels ascending
A. webberi
      9' Awn 13–44 mm, with 1 or 2 bends, persistent
 
        11. Hairs of lemma tip = hairs at lemma midpoint
A. pinetorum
        11' Hairs of lemma tip 1–7 mm, > hairs at midpoint; awn with 1 or 2 bends
 
          12. Awn bent twice; basal leaf blade 2.5–7 mm
A. coronatum
          12' Awn bent once; basal leaf blade 2–3 mm
A. parishii
    8' Hairs of lemma tip < 2 mm
 
      13. Distal segment of awn wavy
A. aridum
      13' Distal segment of awn straight
 
        14. Palea 1/3–2/3 lemma length
 
          15. Internodes above middle with reflexed hairs
A. diegoense
          15' Internodes generally glabrous or inconspicuously hairy at nodes
A. nelsonii subsp. dorei
        14' Palea > 3/4 lemma length
 
          16. Lemma tip 2-toothed, awn-like teeth 1–2 mm; stems 6–15 dm
A. stillmanii
          16' Lemma tip 2-toothed or not, teeth < 1 mm; stems 1.5–9 dm
 
            17. Lemma tip with thick lobe ± 0.1 mm; floret 5.5–7 mm, somewhat compressed
A. lemmonii subsp. lemmonii
            17' Lemma tip with membranous lobe 0.2–1 mm; floret 4.5–6 mm, cylindric
 
              18. Palea thick, stiff, veins evident
A. brachychaetum
              18' Palea thin, flexible, veins obscure
A. lettermanii


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