230 
JOURNAL  OP  HORTICULTURE  AND  COTTAGE  GARDENER. 
March  12,  1903. 
Tlio  Trinity  C'ollogn  Botanic  Gardens  are  important.  Both  the 
Botanic  Gardens  carry  on  valuable  scientitic  work  under  the 
direction  of  Mr.  F.  W.  Moore,  A.L.S.,  at  Glasnevin,  and  Mr. 
F.  W.  Burbidge,  M'.A.,  F.L.S.,  Trinity  College. 
Belfast  posses, ses  a  park  which  compares  well  in  size  with  some 
of  the  large  spaces  in  Knglish  cities,  namely,  Ormeau  Park,  100 
acres  extent.  Victoria  Park  is  63  acres;  Falls  Park,  44  acres; 
Woodvale  Park,  24  acres;  Alexandra  Park,  10  acres;  Dunville 
Park,  4^  acres.  Total  number  of  acres  about  260. 
Pas.sing  to  Wales,  Cardiff  is  the  principal  town,  which  is  pro¬ 
vided  with  parks.  The  leading  enclosure  is  Roath  Park,  combin¬ 
ing  pleasure  and  recreation  grounds,  lake,  and  gardens  of  100 
acres  extent.  Cathays  Park  is  60  acres;  Llandaff  Fields,  59 
acres.  There  are  16  smaller  spaces.  The  total  area  of  pleasure 
grounds  is  250  acres. — Edwin  Dennis  Smith. 
Webb’s  Double  Poppy,  White  Swan. — The  genus  Papaver 
(or  in  English,  Poppy)  furnishes  an  instance  in  which  the  members 
of  it  are,  almost  without  exception,  greatly  prized  as  decorative 
garden  plants,  reciuiring  the  very  slightest  cultural  attention, 
and  thoroughly  prodigal  in  their  supply  of  flpral  brilliance. 
From  the  Opium  Poppy  have  come  the  large  Pasony-flowered 
sorts,  and  we  are  able  to  present  Messrs.  Webb  and  Sons’  variety 
in  the  accompanying  illustration.  So  fine  a  white  as  White 
Swan  is,  must  be  of  the  greatest  utility  for  the  garden  border, 
or  for  corners  and  nooks  in  the  garden.  It  forms  a  companion 
variety  to  others  of  pink  and  crim.son  shades.  A  collection  of 
the  species  and  varieties  of  Poppies  would  be  of  great  interest. 
Ebenlaff  Holes  on  Plant  Distiibution 
Double’’, Poppy,  White  5wan.  Page  235. 
r  HE  distribution  of  plants,  or  geographical  botany,  is  a  si 
^  y  ject  which  is  so  closely  related  to  horticulture,  that 
may  be  deemed  the  one  particular  branch  of  botany  that 
is  more  useful  to  the  gardener  than  any  other  branch  of 
the  science.  And  yet  it  is,  perhaps,  the  one  that  is  the 
most  neglected  by  him.  Probably  many  do  not  realise  that 
great  part  of  the  knowledge  which  is  made  use  of  every  day  in 
the  successful  cultivation  of  plants,  has  been  in  the  past  directly 
or  indirectly  acquired  from  information  that  properly  apper¬ 
tains  to  geographical  botany,  and  therefore  plant  distribution 
does  not  receive  much  attention  at  their  hands.  It  is  therefore 
proposed  to  say  a  few  words  upon  the  subject,  which,  however, 
13  so  vast,  has  so  many  ramifications,  and  is  of  such  an  exceedingly 
complex  nature,  that  nothing  more  can  be  attempted  than  to 
give  a  few  elementary  details  concerning  it  at  this  place. 
In  studying  the  di.stribution  of  plants  it  is  quickly  perceived 
that  any  given  plant  or  assemblage  of  plants  does  not  grow 
everywhere,  but  is  restricted  in  its  range — fir.st,  to  a  certain 
larger  or  smaller  area  of  the  earth’s  .surface;  second,  within  that 
area  is  usually  only  to  be  found  in  certain  favoured  localities. 
This  knowledge  immediately  leads  up  to  the  questions — 1.  Why 
does  a  plant  grow  in  one  place  and  not  in  another,  within  its 
areal  range  ?  2.  By  what  means  does  the  plant  spread  from  one 
place  to  another?  3.  How  is  its  latitudinal  and  longitudinal 
range  limited?  These  questions  apply  to  all  plants,  but  for  the 
sake  of  illustration  it  will  be  convenient  to  follow 
them  out  in  the  case  of  a  common  British  plant,  the 
Primrose  for  example.  In  reference  to  the  first 
question  we  are  all  aware  that  if  we  wish  to  gather 
Primro.'^es  we  shall  have  to  go  to  certain  places  to  get 
them,  and  if  the  general  nature  of  all  the  localities 
where  Primroses  grow  be  noted,  it  will  be  found  that 
as  regards  situation,  general  character,  and  humidity 
of  the  soil,  all  are  very  similar;  and  further,  where 
this  combination  of  conditions  (which  constitute  what 
is  termed  the  habitat  of  a  plant),  do  not  exist  in  a 
degree  necessary  to  the  welfare  of  the  plant,  then  it 
finds  a  limit  to  its  immediate  extension.  This  would 
be  easily  demonstrated  by  transplanting  a  Primrose 
from  the  moist  and  somewhat  stiff  soil  and  slight 
shade  it  delights  in,  to  the  dry  sandy  soil  of  an  open 
common,  where,  even  if  it  lingered  for  a  time,  it 
would  fail  to  establish  itself  and  soon  die  out.  The 
knowledge  of  the  habitat  of  a  plant  is  an  important 
point  to  the  gardener,  for  by  becoming  acquainted 
with  the  nature  and  climate  of  its  habitat,  he  at  once 
knows  the  conditions  under  which  a  plant  is  likelj'  to 
thrive  best  under  cultivation. 
With  reference  to  the  second  question  it  is  obvious 
that  plants  are  chiefly  di.spersed  by  means  of  their 
seeds  or  fruit,  which  are  so  variable  in  size  and  struc¬ 
ture  as  to  be  adapted  to  several  methods  of  di.spersal, 
of  which  the  five  principal  are  as  follows:  1.  Many 
minute  kinds,  or  .such  as  are  provided  with  wings 
(Elm,  Ash,  Maple),  or  with  a  crown  of  hairs  (Thistles, 
Epilobium),  are  carried  long  distances  by  the  wind. 
2.  Many  are  provided  with  hooked  or  barbed  appen¬ 
dages,  which,  becoming  entangled  in  the  fur  and  wool 
of  animals,  may  be  carried  long  distances.  3.  Many 
small  seeds  are  carried  in  the  dirt  adhering  to  the 
feet  of  animals  and  birds.  4.  Some  are  floated  to 
distant  places  by  streams  and  oceanic  currents.  5. 
Some  fleshy  fruits  are  eaten  by  birds  and  the  seeds 
pas.sed  through  them  undigested. 
As  to  the  di.spersion  of  the  Primrose,  although  its 
minute  seeds  may  be  carried  long  distances  by  wind 
storms,  yet  it  is  probable  its  chief  means  of  dispersal  is 
as  stated  under  No.  3,  hares,  rabbits,  mice,  partridges, 
and  other,  small  animals  and  birds  being  the  probable 
distributors.  But  it  by  no  means  follows  that  a  plant 
will  become  established  at  a  distant  spot  because  its 
seeds  are  carried  there,  there  being  many  causes  that 
may  prevent  this.  The  place  to  which  the  seeds  are 
carried  may  not  be  a  .suitable  habitat,  or  if  suitable, 
the  ground  may  be  occupied  by  plants  of  stronger 
growth  with  which  it  cannot  enter  into  competition, 
and  is  starved  out.  If  it  be  a  plant  which  requires 
.some  special  insect  to  fertilise  it,  and  such  insect  is 
absent,  then  the  plant  fails  to  reproduce  itself,  and 
eventually  dies  out.  A  good  example  of  this  wa.s  the 
red  field  Clover,  which  was  .stated  not  to  produce  seed 
in  New  Zealand,  because  the  humble  bees  which  fer¬ 
tilise  it  were  absent  from  that  country.  Finally,  it 
may  be  that  the  young  seedlings  have  no  chance  of 
Sons  surviving,  as  they  may  get  destroyed  by  animals 
browsing,  by  snails,  by  disease,  or  other  causes.  It 
