﻿434 
  T. 
  Holm 
  — 
  Studies 
  in 
  the 
  Cyperacece. 
  

  

  Stereome 
  is 
  well 
  represented 
  in 
  the 
  stem, 
  where 
  it 
  occurs 
  on 
  

   the 
  leptome-side 
  of 
  the 
  outer 
  mestome-bundles 
  and 
  on 
  the 
  

   hadrome-side 
  of 
  the 
  inner 
  ones. 
  In 
  this 
  way 
  it 
  does 
  not 
  form 
  

   any 
  closed 
  ring 
  neither 
  around 
  the 
  single 
  mestome-bundle 
  nor 
  

   around 
  any 
  of 
  the 
  two 
  bands 
  of 
  bundles, 
  which, 
  otherwise, 
  

   seems 
  to 
  be 
  quite 
  common 
  in 
  the 
  stem 
  of 
  the 
  Cyperacece. 
  

  

  The 
  peduncle, 
  the 
  spike-bearing 
  stem, 
  shows 
  very 
  near 
  the 
  

   same 
  structure 
  as 
  we 
  have 
  observed 
  in 
  the 
  main 
  stem. 
  There 
  

   are, 
  however, 
  a 
  few 
  differences 
  to 
  be 
  found, 
  which 
  may 
  be 
  

   noticed 
  here 
  in 
  connection 
  with 
  the 
  stem-structure, 
  since 
  such 
  

   structural 
  divergencies 
  between 
  stem 
  and 
  peduncle 
  have 
  not, 
  

   hitherto, 
  been 
  studied 
  very 
  much. 
  Grevillius,* 
  Laborief 
  and 
  

   Trautwein^: 
  are 
  some 
  of 
  the 
  few 
  authors 
  who 
  have 
  treated 
  this 
  

   subject, 
  and 
  their 
  studies 
  have 
  shown 
  us 
  many 
  interesting 
  

   details 
  in 
  regard 
  to 
  the 
  anatomy 
  of 
  the 
  inflorescential 
  axes 
  in 
  a 
  

   number 
  of 
  plants. 
  

  

  In 
  Dulichium 
  the 
  peduncle 
  is 
  strongly 
  flattened 
  in 
  contrast 
  

   to 
  the 
  cylindric 
  stem, 
  a 
  fact 
  which 
  is 
  due 
  to 
  its 
  tight 
  enclosure 
  

   in 
  the 
  long 
  leaf-sheath. 
  It 
  shows 
  a 
  relative 
  firm 
  structure 
  in 
  

   regard 
  to 
  the 
  development 
  of 
  the 
  mechanical 
  tissue, 
  and 
  is 
  

   solid, 
  not 
  hollow. 
  The 
  epidermis 
  agrees 
  very 
  well 
  with 
  that 
  

   of 
  the 
  stem, 
  but 
  is 
  armed, 
  however, 
  with 
  a 
  few 
  rows 
  of 
  thorn- 
  

   shaped 
  expansions 
  along 
  the 
  two 
  lateral 
  margins. 
  The 
  stomata 
  

   and 
  the 
  interior 
  projections 
  show 
  the 
  same 
  structure 
  and 
  dis- 
  

   tribution 
  as 
  described 
  above 
  as 
  characteristic 
  of 
  the 
  stem. 
  The 
  

   bark-parenchyma 
  contains 
  chlorophyll 
  and 
  surrounds 
  large 
  

   lacunes, 
  which 
  alternate 
  with 
  a 
  corresponding 
  number 
  of 
  mes- 
  

   tome-bundles. 
  

  

  These, 
  the 
  bundles, 
  are 
  arranged 
  in 
  a 
  peripheral 
  band 
  ; 
  

   they 
  are 
  surrounded 
  by 
  a 
  thick-walled 
  parenchyma-sheath, 
  and 
  

   the 
  leptome 
  is 
  often 
  separated 
  from 
  the 
  hadrome 
  by 
  mestome- 
  

   parenchyma 
  of 
  thick-walled 
  cells. 
  The 
  leptome 
  occupies 
  only 
  

   a 
  small 
  part 
  of 
  the 
  bundles, 
  while 
  the 
  hadrome 
  is 
  more 
  fully 
  

   developed 
  with 
  several 
  ring-vessels 
  and 
  generally 
  two 
  large 
  

   pitted-ducts. 
  The 
  stereome 
  forms 
  large 
  groups 
  around 
  the 
  

   mestome-bundles. 
  Tannin-reservoirs 
  are, 
  also, 
  present 
  in 
  the 
  

   peduncle, 
  where 
  they 
  were 
  observed 
  in 
  the 
  bark 
  close 
  to 
  the 
  

   lacunes, 
  but 
  not 
  in 
  the 
  large, 
  colorless 
  parenchyma, 
  which 
  

   occupies 
  the 
  center 
  of 
  the 
  peduncle. 
  

  

  This 
  is 
  the 
  general 
  structure 
  of 
  the 
  peduncle 
  underneath 
  

   the 
  spike-bearing 
  part, 
  the 
  rhachis, 
  and 
  we 
  notice 
  by 
  examin- 
  

   ing 
  this 
  a 
  certain 
  change 
  in 
  structure, 
  which 
  is, 
  especially, 
  due 
  

  

  * 
  Grevillius, 
  A. 
  I. 
  Anatomiska 
  studier 
  cefver 
  de 
  florala 
  axlarna 
  hos 
  diklina, 
  

   Fanerogainer, 
  Bihang 
  Kgl. 
  Svenska 
  Yet, 
  Akad. 
  Hdlgr., 
  vol. 
  xvi. 
  Stockholm 
  

   1890. 
  

  

  f 
  Laborie, 
  E. 
  Anatoraie 
  des 
  axes 
  floraux 
  Kevue 
  scientifique, 
  vol. 
  xliv, 
  

   Paris, 
  1888. 
  

  

  \ 
  Trautwein, 
  J. 
  Ueber 
  Anatomie 
  eiojahriger 
  Zweigeund 
  Bluthenstandsachsen 
  r 
  

   Inaug. 
  diss, 
  Halle, 
  1885. 
  

  

  