﻿360 
  T. 
  Holm 
  — 
  Studies 
  in 
  the 
  Gyperacece. 
  

  

  The 
  stem, 
  

  

  this 
  is 
  terete 
  and 
  hollow 
  in 
  all 
  three 
  species, 
  sulculate 
  in 
  G. 
  

   elynoides 
  and 
  G. 
  filifolia, 
  smooth 
  in 
  G. 
  oreocharis 
  / 
  a 
  few 
  

   curved 
  prickle-like 
  projections 
  are 
  observable 
  in 
  G. 
  filifolia, 
  

   but 
  in 
  the 
  two 
  other 
  species 
  the 
  culm 
  is 
  glabrous. 
  The 
  cuticle 
  

   is 
  smooth 
  and 
  very 
  distinct. 
  Epidermis 
  thick-walled, 
  except- 
  

   ing 
  those 
  cells 
  which 
  contain 
  the 
  silicious 
  cones, 
  and 
  which 
  are 
  

   observable 
  outside 
  the 
  stereome. 
  The 
  stomata 
  are 
  level 
  with 
  

   the 
  surrounding 
  epidermis, 
  and 
  are 
  not 
  protected 
  by 
  any 
  

   papillse, 
  nor 
  are 
  the 
  subsidiary 
  cells 
  raised 
  above 
  the 
  guard- 
  

   cells 
  themselves. 
  In 
  the 
  sulculate 
  stems 
  the 
  stomata 
  are, 
  

   furthermore, 
  equally 
  distributed 
  outside 
  the 
  cortex, 
  without 
  

   being 
  confined 
  to 
  the 
  bottom 
  of 
  the 
  furrows, 
  or 
  along 
  the 
  sides 
  

   of 
  them. 
  The 
  cortex 
  consists 
  of 
  palisades, 
  radiating 
  towards 
  

   the 
  center 
  of 
  the 
  stem 
  and 
  shows 
  wide 
  lacunes 
  in 
  G. 
  elynoides 
  

   and 
  G. 
  oreocharis 
  ; 
  in 
  G. 
  Jllifolia, 
  on 
  the 
  other 
  hand, 
  the 
  pali- 
  

   sade-tissue 
  is 
  very 
  compact 
  and 
  persisting. 
  The 
  stereome 
  is 
  

   very 
  thick-walled 
  in 
  G. 
  oreocharis, 
  but 
  not 
  so 
  in 
  the 
  other 
  

   species 
  : 
  it 
  occurs 
  as 
  hypodermal 
  groups 
  accompanying 
  the 
  large 
  

   mestome-bundles, 
  besides 
  that 
  it 
  also 
  covers 
  the 
  hadrome-side 
  

   of 
  these, 
  bordering 
  on 
  the 
  pith 
  ; 
  the 
  smaller 
  mestome-bundles 
  

   have 
  but 
  very 
  little 
  stereome 
  on 
  either 
  face, 
  separated 
  from 
  

   epidermis 
  by 
  the 
  palisade-tissue. 
  All 
  the 
  mestome-bundles 
  lie 
  

   in 
  one 
  peripheral 
  band, 
  larger 
  alternating 
  with 
  smaller 
  ones 
  ; 
  

   they 
  are 
  surrounded 
  by 
  a 
  green, 
  thin-walled 
  parenchyma- 
  

   sheath, 
  inside 
  of 
  which 
  we 
  find 
  the 
  usual 
  mestome-sheath, 
  

   which 
  is 
  heavily 
  thickened 
  in 
  G 
  oreocharis, 
  less 
  so 
  in 
  the 
  

   other 
  species. 
  Some 
  few 
  strata 
  of 
  thick-walled 
  mestome- 
  

   parenchyma 
  were 
  observed 
  between 
  the 
  leptome 
  and 
  hadrome 
  

   at 
  least 
  in 
  the 
  larger 
  bundles 
  of 
  all 
  these 
  species. 
  The 
  pith 
  

   consists 
  of 
  a 
  very 
  thin- 
  walled 
  parenchyma 
  which 
  breaks 
  down, 
  

   leaving 
  a 
  wide 
  cavity 
  in 
  the 
  center 
  of 
  the 
  stem. 
  In 
  comparing 
  

   this 
  stem-structure 
  with 
  that 
  of 
  the 
  other 
  Gyperacem 
  in 
  gen- 
  

   eral, 
  our 
  species 
  seem 
  well 
  characterized 
  by 
  possessing 
  a 
  terete 
  

   and 
  hollow 
  stem, 
  instead 
  of 
  a 
  triangular 
  and 
  solid 
  one 
  as 
  in 
  the 
  

   majority 
  of 
  the 
  other 
  species, 
  at 
  least 
  in 
  Garex. 
  

  

  The 
  leaf 
  

  

  offers 
  excellent 
  characters 
  by 
  which 
  these 
  species 
  may 
  be 
  

   readily 
  distinguished 
  from 
  each 
  other, 
  and 
  we 
  find 
  in 
  G 
  ely- 
  

   noides 
  exactly 
  the 
  same 
  leaf 
  structure 
  as 
  we 
  have 
  observed 
  in 
  

   Elyna 
  spicata. 
  The 
  broadest 
  leaf 
  is 
  possessed 
  by 
  G. 
  oreocharis 
  

   from 
  an 
  elevation 
  of 
  8,600 
  feet, 
  and 
  the 
  narrowest 
  by 
  G. 
  ely- 
  

   noides 
  from 
  the 
  high 
  alpine 
  slopes. 
  The 
  width 
  of 
  the 
  leaf 
  of 
  

   G. 
  filifolia 
  from 
  the 
  foothills 
  is 
  intermediate 
  between 
  these 
  

   two 
  species. 
  The 
  leaf 
  is 
  not 
  flat 
  in 
  any 
  of 
  tliese 
  species, 
  but 
  

  

  