﻿52 
  BOTANICAL 
  GAZETTE. 
  [ 
  Murch, 
  

  

  to 
  procure 
  specimens. 
  Lil^e 
  so 
  many 
  of 
  the 
  ferns 
  of 
  the 
  

   southwest 
  Its 
  fronds 
  are 
  curled 
  up 
  in 
  summer 
  in 
  brittle 
  knots 
  

   that 
  crumble 
  at 
  the 
  touch, 
  but 
  expand 
  and 
  live 
  again 
  at 
  the 
  

   coming 
  of 
  the 
  rainy 
  season. 
  In 
  their 
  exposed 
  situation 
  the 
  

   Slover 
  Nothol^enas 
  lead 
  an 
  unusually 
  intermittent 
  life, 
  un- 
  

   rolling 
  their 
  fronds 
  at 
  every 
  shower 
  and 
  contracting 
  them 
  

   again 
  with 
  every 
  dry 
  wind 
  from 
  the 
  north. 
  The 
  wliite-pow- 
  

   dered 
  form 
  and 
  the 
  yellow-powdered 
  are 
  equally 
  abundant, 
  

   but 
  the 
  plants 
  are 
  smaller 
  than 
  those 
  of 
  the 
  desert, 
  where 
  

   they 
  often 
  grow 
  about 
  the 
  edges 
  of 
  boulders 
  w 
  ith 
  their 
  roots 
  

   in 
  the 
  soil 
  beneath. 
  It 
  is 
  also 
  found 
  on 
  the 
  drv 
  hills 
  about 
  

   San 
  Diego, 
  where 
  several 
  desert 
  plants 
  reach 
  the 
  sea. 
  Our 
  

   station 
  is 
  perhaps 
  the 
  westernmost 
  one. 
  It 
  certainly 
  is 
  oi 
  

   Erodiwn 
  Texanum 
  Graj', 
  whose 
  eastern 
  origin 
  is 
  indicated 
  by 
  

   its 
  name, 
  and 
  which 
  I 
  have 
  collected 
  on 
  the 
  very 
  summit. 
  

   Elsewhere 
  in 
  this 
  state 
  it 
  has 
  been 
  found 
  springing 
  up 
  at 
  a 
  

   few 
  places 
  on 
  the 
  Mojave 
  and 
  the 
  Colorado 
  deserts. 
  

  

  Allium 
  unifolium 
  Kellogg, 
  abundant 
  on 
  a 
  stony 
  northern 
  

   slope, 
  belongs 
  to 
  the 
  west 
  and 
  north, 
  in 
  the 
  coast 
  range, 
  and 
  

   finds 
  here 
  its 
  eastern 
  limit. 
  Sisymbrium 
  refexum 
  Nutt., 
  and 
  

   Amsinchia 
  intermedia 
  F. 
  & 
  M., 
  are 
  to 
  be 
  noted 
  as 
  occurring 
  

   here, 
  quite 
  away 
  from 
  their 
  usual 
  range. 
  Both 
  are 
  not 
  un- 
  

   common 
  on 
  the 
  edge 
  of 
  the 
  deserts, 
  and 
  the 
  latter 
  is 
  also 
  re- 
  

  

  ported 
  to 
  grow 
  near 
  the 
  coast. 
  

  

  Dclpiiiiiium 
  Pi 
  

  

  ishii 
  Gray, 
  which 
  has 
  as 
  yet 
  been 
  discovered 
  nowhere 
  else. 
  

   Its 
  aspect 
  suggests 
  that 
  it 
  also 
  may 
  be 
  an 
  outlying 
  member 
  

   of 
  the 
  desert 
  flora. 
  

  

  Why 
  this 
  insignificant 
  hill 
  should 
  have 
  so 
  peculiar 
  a 
  flora 
  

   is 
  an 
  interesting 
  problem 
  in 
  geographical 
  botany. 
  That 
  

   a 
  particular 
  species 
  should 
  be 
  found 
  only 
  in 
  a 
  certain 
  spot, 
  or 
  

   at 
  least 
  not 
  in 
  any 
  similar 
  one 
  for 
  many 
  miles 
  in 
  any 
  direc- 
  

   tion, 
  is 
  not 
  uncommon 
  in 
  this 
  region. 
  It 
  is 
  true 
  that 
  this 
  

   isolation 
  in 
  some 
  cases 
  may 
  be 
  only 
  seeming, 
  and 
  due 
  to 
  a 
  

   lack 
  of 
  thorough 
  knowledge 
  of 
  the 
  surrounding 
  country, 
  but 
  

   It 
  occurs 
  too 
  frequently 
  in 
  well 
  explored 
  ground 
  not 
  to 
  be 
  

   accepted 
  as 
  real. 
  It 
  is 
  indeed 
  one 
  of 
  the 
  characteristics 
  of 
  

   our 
  flora. 
  

  

  But 
  here 
  we 
  have 
  not 
  one, 
  as 
  is 
  usual, 
  but 
  seven 
  isolated 
  

   species 
  gathered 
  together 
  in 
  an 
  area 
  of 
  a 
  few 
  acres. 
  The 
  

   geological 
  formation 
  of 
  the 
  mountain, 
  so 
  different 
  from 
  its 
  

   neighbors, 
  might 
  appear 
  to 
  account 
  for 
  its 
  peculiar 
  vegeta- 
  

   tion. 
  But 
  in 
  other 
  places 
  none 
  of 
  these 
  species 
  grow 
  in 
  cal- 
  

   careous 
  soil, 
  nor 
  are 
  they 
  to 
  be 
  found 
  on 
  another 
  outcrop- 
  

  

  