﻿516 
  Nichols: 
  The 
  vegetation 
  of 
  Connecticut 
  

  

  is 
  undisturbed 
  by 
  wave 
  action, 
  but 
  during 
  winter 
  It 
  is 
  frequently 
  

   swept 
  by 
  the 
  sea 
  and 
  sometimes 
  becomes 
  completely 
  covered 
  over 
  

   with 
  ice. 
  Obviously 
  conditions 
  here 
  are 
  not 
  suitable 
  either 
  for 
  

   seaweeds 
  or 
  for 
  perennial 
  land 
  plants. 
  The 
  characteristic 
  inhabi- 
  

   tants 
  are 
  xerophytic 
  annual 
  seed 
  plants: 
  species 
  which 
  in 
  divers 
  

   ways* 
  are 
  adapted 
  to 
  withstand 
  the 
  exposure 
  to 
  strong 
  winds, 
  

   intense 
  illumination, 
  and 
  high 
  temperatures 
  to 
  which 
  plants 
  

   growing 
  on 
  the 
  open 
  beach 
  are 
  constantly 
  being 
  subjected 
  during 
  

   the 
  growing 
  season. 
  f 
  The 
  plant 
  cover 
  on 
  the 
  middle 
  beach 
  is 
  

  

  * 
  Adaptation 
  to 
  a 
  xerophytic 
  environment 
  on 
  the 
  part 
  of 
  beach 
  and 
  dune 
  plants 
  

  

  I 
  

  

  is 
  seen 
  particularly 
  in 
  their 
  peculiarities 
  of 
  leaf 
  structure. 
  Thus, 
  of 
  the 
  various 
  species 
  

   to 
  be 
  listed 
  as 
  characteristic 
  of 
  middle 
  or 
  upper 
  beach, 
  Salsola, 
  Cakile, 
  and 
  Arenaria 
  

   have 
  leaves 
  which 
  are 
  conspicuously 
  succulent, 
  Atriplex 
  and 
  Lathyrus 
  have 
  semi- 
  

   succulent 
  leaves, 
  and 
  Xanthiiim 
  has 
  hard, 
  thick 
  leaves; 
  the 
  leaf 
  surface 
  in 
  Cheno- 
  

   podium 
  and 
  Atriplex 
  is 
  covered 
  with 
  a 
  granular-waxy 
  coating, 
  and 
  in 
  Euphorbia 
  and 
  

   Lathyrus 
  with 
  a 
  waxy 
  "bloom;" 
  the 
  leaves 
  of 
  Artemisia 
  Stelleriana 
  are 
  densely 
  

   tomentose; 
  while 
  those 
  of 
  Ammophila 
  are 
  erect, 
  stiff, 
  and 
  conspicuously 
  involute. 
  

   Moreover, 
  in 
  Euphorbia 
  the 
  entire 
  aerial 
  system 
  of 
  the 
  plant 
  exhibits 
  a 
  prostrate 
  

   "radiant" 
  habit 
  — 
  a 
  habit 
  also 
  possessed, 
  though 
  to 
  a 
  less 
  pronounced 
  degree, 
  by 
  

   the 
  shoot 
  in 
  several 
  other 
  beach 
  plants. 
  In 
  addition 
  to 
  these 
  peculiarities 
  of 
  the 
  

   shoot 
  system, 
  which 
  are 
  associated 
  either 
  with 
  the 
  storage 
  of 
  water 
  or 
  its 
  conservatTon 
  

   (through 
  reduction 
  of 
  transpiration), 
  the 
  root 
  system 
  in 
  beach 
  and 
  dune 
  plants 
  is 
  so 
  

   developed 
  as 
  to 
  make 
  the 
  most 
  of 
  the 
  available 
  water 
  supply: 
  a 
  supply 
  which, 
  though 
  

   scanty 
  in 
  the 
  surface 
  layers 
  of 
  sand, 
  is 
  usually 
  quite 
  abundant 
  at 
  depths 
  of 
  from 
  six 
  

   inches 
  to 
  a 
  foot. 
  The 
  various 
  annual 
  species 
  have 
  a 
  prominent 
  tap-root, 
  as 
  have 
  

   some 
  of 
  the 
  perennials, 
  and 
  the 
  usually 
  abundant 
  secondary 
  roots 
  radiate 
  horizontally 
  

   for 
  considerable 
  distances. 
  Paucity 
  of 
  mineral 
  and 
  organic 
  nutrients 
  in 
  the 
  soil 
  

   doubtless 
  is 
  a 
  factor 
  which 
  markedly 
  affects 
  the 
  character 
  of 
  beach 
  and 
  dune 
  vegeta- 
  

   tion, 
  and 
  which 
  may 
  be 
  largely 
  responsible 
  for 
  the 
  absence 
  here 
  of 
  many 
  plants 
  that 
  

   are 
  found 
  in 
  dry 
  soils 
  elsewhere. 
  

  

  t 
  For 
  many 
  years 
  the 
  plants 
  of 
  sea 
  beaches, 
  like 
  those 
  of 
  salt 
  marshes, 
  were 
  

   generally 
  regarded 
  as 
  true 
  halophytes. 
  Kearney 
  (^04), 
  however, 
  has 
  shown 
  that 
  the 
  

   amount 
  of 
  salt 
  present 
  in 
  the 
  sand 
  of 
  the 
  middle 
  and 
  upper 
  beaches 
  at 
  the 
  height 
  of 
  

   the 
  growing 
  season 
  is 
  in 
  reality 
  very 
  slight. 
  At 
  a 
  station 
  along 
  the 
  Massachusetts 
  

   coast, 
  in 
  July, 
  for 
  example, 
  the 
  sand 
  of 
  tlie 
  middle 
  beach, 
  near 
  the 
  lower 
  limits 
  of 
  

   vegetation, 
  was 
  found 
  to 
  contain 
  only 
  0.003 
  per 
  cent, 
  or 
  less, 
  of 
  salt 
  (as 
  compared 
  

   with 
  1.4-2.6 
  per 
  cent 
  in 
  the 
  soil 
  of 
  a 
  nearby 
  salt 
  marsh). 
  At 
  certain 
  seasons, 
  of 
  

   course, 
  salt 
  may 
  be 
  present 
  in 
  relatively 
  large 
  amount, 
  but 
  in 
  regions 
  of 
  abundant 
  

   precipitation 
  it 
  is 
  rapidly 
  leached 
  out 
  by 
  percolating 
  rain 
  water. 
  The 
  plants 
  of 
  sea 
  

   beaches, 
  then, 
  "are 
  not 
  generally 
  halophytes, 
  in 
  the 
  same 
  sense 
  that 
  the 
  plants 
  of 
  

   inland 
  saline 
  situations 
  are, 
  but 
  are 
  for 
  the 
  most 
  part 
  merely 
  such 
  plants 
  of 
  normally 
  

   non-saline 
  habitats 
  as 
  are 
  able 
  to 
  withstand 
  a 
  high 
  salt 
  concentration 
  without 
  injury" 
  

   (Bartlett, 
  '09). 
  Nevertheless, 
  it 
  is 
  a 
  fact, 
  to 
  quote 
  further 
  from 
  Bartlett. 
  ''that 
  a 
  

   large 
  proportion 
  of 
  the 
  species 
  of 
  the 
  beach 
  and 
  transition 
  zone 
  floras. 
  althoTigh 
  not 
  

   necessarily 
  always 
  found 
  within 
  the 
  limits 
  of 
  tide 
  water, 
  are, 
  nevertheless, 
  seldom 
  

   found 
  more 
  than 
  a 
  few 
  miles 
  from 
  the 
  ocean." 
  Bartlett 
  suggests 
  that 
  it 
  may 
  be 
  

  

  