June  25,  1903. 
5£3 
JOUBNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
Odontoglossum  cirrhosum,  Pitt's  var. 
This  elegant  variety  was  staged  at  the  Royal  Horticultural 
Society’s  meeting  by  Mr.  H.  T.  Pitt  (gardener,  Mr.  Thurgood), 
Rosslyn,  Stamford  Hill,  on  May  o.  The  segments  are  all  much 
enlarged,  being  broad  and  smooth  towards  the  base,  and"  beauti¬ 
fully  spotted  with  reddish  jDurple.'  The  variety  wr,s  much 
admired  by  fanciers  of  Odontoglossums,  and  it  received  an 
Award  of  Merit. 
The  Week’s  Cultural  Notes. 
Dendrobium  Bensonise,  one  of  the  prettiest  of  the  Dendro- 
biums  now  in  flower,  must  be  considered  a  difficult  subject  to 
grow.  Although  for  a  few  years  after  importation  it  grows 
away  fairly  well,  it  never  increases  in  size  much  under  cultiva¬ 
tion,  and  the  number  of  healthy  si^ecimens  of,  say,  ten  years’ 
growth  in  this  country  must  be  few  indeed,  considering  the 
immense  number  sent  home.  D.  Parishi  is  another  difficult 
Ijlant  ;  it  is  quite  different  in  habit  and  flower  from  the  above- 
named,  though  almost  equally  beautiful  with  its  mauve  and 
ljurple  flowers. 
Baskets  or  small  suspended  iDans  are  best  for  either  of  them, 
a  thin  compost  of  peat  and  moss  over  exceptionally  good 
drainage,  and  a  regularly  moist  atmosphere  all  the  year  round. 
It  seems  hardly  necessary  to-  repeat  that  the  plants  must  be 
very  firmly  tied  in  ijosition ;  but  this  is  one  of  the  points  that 
is  most  frequently  lost 
sight  of  by  amateur 
growers,  and  it  has  caused 
the  loss  of  more  Orchids 
than  any  other  detail  of 
mismanagement.  Fro  m 
D.  Bensonise  and  its  allies 
to  the  large  and  noble 
D.  moschatum  is  a  far 
cry.  This  also  is  in  flower 
now,  iDi’oducing  lax 
racemes  of  large  golden 
yellow  blossoms  from  the 
upper  portions  of  the  last 
year’s  stems,  these  often 
being  from  10ft  to  12ft  in 
length.  Such  a  plant  as 
this  obviously  needs  a 
larger  amount  of  suste¬ 
nance  than  the  majorits' 
of  Orchids,  and  after 
flowering,  when  the  young 
tiers  of  roots  are  issuing 
from  the  base  of  the  young 
stems,  is  the  time  for 
attention.  If  in  a  large 
pot  or  basket,  as  it  should 
be,  it  will  usually  be  suffi¬ 
cient  to  I'emove  as  much 
as  possible  of  the  old  sour 
material,  and  replace  it 
with  new,  using  lumpy 
peat,  siihagnum  moss,  and 
large  nodules  of  crocks  and 
charcoal.  As  the  large 
roots  jiush  through  this  a 
very  free  supply  of 
moisture  is  necessai’y  to 
them,  and  this,  combined 
with  abundant  heat,  will 
cause  the  growth  to  be 
very  free  and  rapid. 
The  growing  season  of 
this  iflant  is  spread  over 
many  months,  for  it  has  a 
lot  to  do,  and  as  a  rule  it 
is  impossible  to  finish  and 
ripen  the  stems  in  one  season.  This  being  the  case,  the  flower 
spikes  are  produced  on  the  older  stems,  those  of  two  and  more 
years  old.  These  should  not  bo  removed  then  until  it  is  quite 
apparent  that  they  are  di-jdng  up  and  have  ceased  to  be  of  any 
value  to  the  plant.  So  far  the  season  has  been  anything  but 
satisfactory  for  the  growth  of  Orchids,  and  a  great  deal  more 
fire  heat  than  usual  has  been  neoessaiy.  Tliis  must  be  softened 
down  with  moisture,  and  great  care  exercised  in  ventilation, 
too  little  air  causing  a  weak  growth,  while  widely  opened  lights 
caiLse  draught  and  severe  checks  to  growth. — H.  R.  R. 
Cactaceous  Plants:  Pereskias.” 
{Concluded  from  page  dSG.) 
The  genus  Pereskia  is  chiefly  interesting  on  account  of  the 
link  which  it  appears  to  form  with  ordinary  vegetation.  They 
run  into  the  Opuntias  also,  but  may  be  distinguished  from  them 
by  their  black  and  comparatively  soft  seeds  and  barbless  spines. 
There  are  several  species,  most  of  them  native  of  the  forests  of 
Tropical  America  and  the  West  Indies.  P.  aculeata  is  well 
known  as  a  stock  for  Epiphyllums  and  other  epiphytal  Cacti.  It 
is  commonly  called  the  Barbadoes  Gooseberry.  P.  amapola  is 
used  in  Paraguay  for  forming  hedges.  Had  we  come  to  blows 
with  Venezuela  in  ’97,  our  troops  would  probably  havm  made  the 
unpleasant  acquaintance  of  Pereskia  Guanacho,  in  the  Valley  of 
the  Orinoco,  where  the  natives  make  impenetrable  hedges  with 
it.  The  sub-species  aquosa  is  a  new  one  from  Mexico.  At 
Guadalajara  it  is  cultivated  by  the  working  population  against 
walls  for  the  sake  of  its  fruits,  which  resemble  Cherries,  and 
these  are  sold  in  the  small  markets,  being  valuable  as  winter 
fruit.  Most  of  the  species  need  plenty  of  heat  and  moistui'e,  but 
those  growing  in  the  mountainous  districts,  at  high  elevations, 
will  thrive  under  ordinary  greenhouse  treatment. 
General  Summary, 
The  Cactacese  are  natives  of  the  American  Continent.  They  are 
found  in  the  largest  numbers  in  Mexico ;  from  that  country  they 
extend  as  far  north  as  British  Columbia  and  as  far  south  as  Pata¬ 
gonia.  Some  inhabit  the  warm  plains  and  forests,  and  others  are 
happy  on  the  rocky  slopes  of  the  Andes,  Rockies,  and  other 
mountains,  where  frost  and  snow  is  experienced,  6,000ft  to 
15,000ft  above  sea  level.  They  are  also  found  on  the  numerous 
islands  of  the  Great  and  Lesser  Antilles.  On  the  Pacific  side 
they  abound  on  several  of  the  islands,  the  most  westerly  being 
the  Galapagos  group,  which  lies  about  500  miles  from  the  coast 
of  Ecuador,  and  at  least 
six  species  of  Cereus  and 
Opuntia  are  known  to  exist 
in  this  group,  being  ap¬ 
parently  very  different 
from  those  of  the  main¬ 
land.  They  serve*  princi¬ 
pally  as  food  for  the 
gigantic  tortoises  and 
lizards,  and  are  said  to 
form  the  only  source  of 
water  supply  on  some  of 
the  islands  of  the  group. 
It  is  erroneously  sup¬ 
posed  that  Cacti  are  in¬ 
digenous  to  South  Africa. 
The  only  genus  which  is  a 
native  of  the  Old  World  is 
the  Rhipsalis,  found  in 
Madagascar,  Mauritius, 
and  Zanzibar.  The  Cacti 
one  used  to  read  of  in  the 
war  news  are  Opuntias  of 
the  Prickly  Pear  section, 
which  have  become  natu¬ 
ralised  in  certain  parts  of 
South  Africa;  or  possibly 
some  of  the  Euphorbias 
have  been  mistaken  for 
them  owing  to  their  I’esem- 
blance  to  some  of  the 
species. 
The  Cactus  plays  a  vei-y 
importaut  part  in  the 
economy  of  Nature.  It  is 
to  the  American  desert 
what  the  oasis  is  to  the 
African.  Both  man  and 
beast  would  often  succumb 
from  thirst  and  hunger 
were  it  not  for  the  succu¬ 
lent  Cactus.  Man,  by 
cutting  the  top  off  a  large 
Ecliinocactus  and  forming 
a  hollow  cup  in  the  stump, 
which  soon  fills  with  the 
juices  of  the  plant,  is  able 
to  quench  his  thirst.  The  fruit  of  the  Opuntia  will  also  serve  him 
for  food.  The  wild  horses  and  mules  use  their  hard  hoofs  for 
smashing  up  the  plants,  and  so  are  able  to  get  at  their  soft 
cellular  tissue  for  food,  when  no  other  sustenance  is  to  be 
obtained. 
In  the  deserts  of  America  large  masses  of  Opuntia  ate  often 
found  growing  on  mounds.  These  mounds,  on  examination,  are 
Odontoglossum  cirrhosum,  Pitt’s  var. 
*  A  paper  re.ad  at  Manchester  by  Mr.  Arthur  Cotbohl,  Holly  Point,  Heaton  Mersey. 
