﻿GLOSSARY 
  355 
  

  

  Rhizome. 
  See 
  Rootstock. 
  

  

  Rootstock. 
  A 
  horizontal, 
  more 
  or 
  less 
  thickened, 
  root-like 
  stem, 
  either 
  

   on 
  the 
  ground 
  or 
  underground. 
  

  

  Saprophyte. 
  An 
  organism 
  that 
  obtains 
  its 
  food 
  from 
  dead 
  or 
  decay- 
  

   ing 
  organisms. 
  

  

  Scalariform 
  (ladder 
  form). 
  A 
  name 
  applied 
  to 
  ducts 
  with 
  piths 
  hori- 
  

   zontally 
  elongated, 
  and 
  so 
  placed 
  that 
  the 
  intervening 
  thickening 
  ridges 
  

   appear 
  like 
  the 
  rounds 
  of 
  a 
  ladder. 
  

  

  Scale 
  (a 
  flight 
  of 
  steps). 
  Any 
  thin 
  scarious 
  body, 
  as 
  a 
  degenerated 
  

   leaf, 
  or 
  flat 
  hair. 
  

  

  Sclerenchyma. 
  A 
  tissue 
  composed 
  of 
  cells 
  that 
  are 
  thick-walled, 
  often 
  

   extremely 
  so. 
  

  

  Seed. 
  The 
  matured 
  ovule. 
  

  

  Sepal. 
  A 
  calyx 
  leaf. 
  

  

  Seta; 
  pi. 
  setae. 
  A 
  bristle, 
  or 
  bristle-shaped 
  body; 
  in 
  mosses, 
  the 
  stalk 
  

   of 
  the 
  capsule. 
  

  

  Sexual 
  spore. 
  One 
  formed 
  by 
  the 
  union 
  of 
  cells. 
  

  

  Sheath. 
  A 
  thin 
  enveloping 
  part, 
  as 
  of 
  a 
  filament, 
  leaf, 
  or 
  resin 
  duct. 
  

  

  Sieve 
  cells. 
  Cells 
  belonging 
  to 
  the 
  phloem, 
  and 
  characterized 
  by 
  the 
  

   presence 
  of 
  perforated 
  plates 
  in 
  the 
  wall. 
  

  

  Sorus 
  (a 
  heap) 
  ; 
  pi. 
  sori. 
  In 
  ferns, 
  the 
  groups 
  of 
  sporangia, 
  constitut- 
  

   ing 
  the 
  so-called 
  " 
  fruit 
  dots 
  " 
  ; 
  in 
  parasitic 
  fungi, 
  well-defined 
  groups 
  

   of 
  spores, 
  breaking 
  through 
  the 
  epidermis 
  of 
  the 
  host. 
  

  

  Sperm, 
  or 
  Spermatozoid 
  (animal-like 
  sperm). 
  The 
  male 
  gamete. 
  

  

  Spermatophytes 
  (seed 
  plants). 
  The 
  highest 
  great 
  group 
  of 
  plants, 
  of 
  

   which 
  a 
  characteristic 
  structure 
  is 
  the 
  seed. 
  

  

  Spike. 
  A 
  flower 
  cluster, 
  having 
  its 
  flowers 
  sessile 
  on 
  an 
  elongated 
  

   axis. 
  

  

  Spikelet 
  (diminutive 
  of 
  spike). 
  A 
  secondary 
  spike; 
  in 
  grasses, 
  the 
  

   ultimate 
  flower 
  cluster, 
  consisting 
  of 
  one 
  or 
  more 
  flowers 
  subtended 
  by 
  

   a 
  common 
  pair 
  of 
  glumes. 
  

  

  Sporangium 
  (spore 
  vessel) 
  ; 
  pi. 
  sporangia. 
  The 
  spore-producing 
  

   structure. 
  

  

  Spore 
  (seed). 
  Originally 
  used 
  as 
  the 
  analogue 
  of 
  seed 
  in 
  flowerless 
  

   plants 
  ; 
  now 
  applied 
  to 
  any 
  one-celled 
  or 
  few-celled 
  body 
  which 
  is 
  sepa- 
  

   rated 
  from 
  the 
  parent 
  for 
  the 
  purpose 
  of 
  reproduction, 
  whether 
  sexually 
  

   or 
  asexually 
  produced 
  ; 
  the 
  different 
  methods 
  of 
  its 
  production 
  are 
  in- 
  

   dicated 
  by 
  suitable 
  prefixes. 
  

  

  Sporogonium 
  (spore 
  offspring) 
  ; 
  pi. 
  sporogonia. 
  The 
  whole 
  structure 
  

   of 
  the 
  spore-bearing 
  stage 
  of 
  bryophytes. 
  

  

  Sporophyll. 
  A 
  leaf 
  that 
  bears 
  sporangia. 
  

  

  Sporophyte 
  (spore 
  plant). 
  The 
  asexual 
  or 
  spore-producing 
  stage 
  of 
  

   an 
  alternating 
  plant. 
  

  

  