204 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
March  6,  19021. 
Plant  Hybridisation. 
Dr.  J.  H.  Wilson’s  lecture  to  the  Scottish  Horticultural 
Association  on  Tuesday,  Feb.  4,  being  of  surpassing  interest,  a 
few  supplementary  notes  to  the  report  which  appeared  in  a  former 
issue  may  be  acceptable  to  many  readers  of  the  Journal  of 
Horticulture.  Introducing  his  subject  the  genial  doctor  remarked 
that  Nature  in  its  normal  condition  would,  no  doubt,  in  the  course 
of  time  evolve  improvements  of  species,  but  this  being  merely 
chance,  the  skill  of  the  hybridiser,  and  the  work  of  selection  must 
be  brought  to  bear  upon  it  in  order  to  arrive  at  the  end  in  view 
as  quickly  as  possible. 
The  first  illustration  he  showed  upon  the  screen  was  a  very 
floriferous  Oriental  Poppy,  a  hybrid  between  P.  pilosnm  and 
P.  orientale.  P.  orientale 
being  rather  a  shy  flowerer, 
he  desired  to  raise  a  hybrid 
which  would  remedy  this 
defect,  and  was  so  success¬ 
ful  in  his  effort  that  on  the 
plant  in  question  over  forty 
buds  could  be  counted  in 
different  stages  of  develop¬ 
ment.  Sad  to  relate,  how¬ 
ever,  this  fine  plant  suc¬ 
cumbed  to  the  rigors  of  a 
hard  wdnter. 
As  his  second  illustra¬ 
tions  he  said  he  wdshed  to 
obtain  an  intermediate 
colour  between  Centaurea 
candidissima  and  a  native 
species  growing  wild  along 
the  Fifeshire  coast,  the  first 
having  a  yellow  and  the  last 
a  fine  purple  flower.  He 
crossed  these  two,  and  the 
result  was  a  hybrid  with 
foliage  truly  intermediatei, 
butithas  notas  yetflowered. 
Hybrids  of  Digitalis  lutea 
and  D.  purpurea  flowered 
profusely,  many  showing 
very  fine  markings,  and  a 
white  variety  was  exceed¬ 
ingly  beautiful,  throwing 
spikes  8ft  high,  yet  never 
bearing  a  single  seed. 
Variegation  in  plants  being 
an  extremely  interesting 
study.  Dr.  Wilson  .said  he 
would  draw’  attention  to 
one  or  two  points  regarding 
the  matter. 
In  some  plants  this  trait 
is  very  pronounced,  show’- 
ing  even  in  the  seeds  and 
cotyledons.  Illustrations  of 
variegated  Pelargoniums, 
showing  how  the  variega¬ 
tion  w’eakened  the  growth, 
and  Abutilon  (vexillariuin) 
megapotamicum,  inarched 
on  to  a  green  hybrid,  with 
traces  of  the  variegation 
descending  into  the  green 
plants,  w’ere  exceedingly  in¬ 
teresting.  Being  at  one 
time  an  enthusiastic  culti¬ 
vator  of  Begonias,  the 
doctor  made  some'  interest¬ 
ing  experiments  with  them. 
By  croissing  the  tuberous  Begonia  with  B.  coccinea,  the  seeds 
ripened  well,  and  a  good  quantity  of  fine  healthy  seedlings  was 
tne  result,  these  having  flourished  all  summer  without  showing 
flower,  and  making  no  root  growth  in  the  form  of  a  tuber,  he  had 
watched  carefully  what  habit  they  would  assume  during  the 
^o^g  a  great  part  of  their  foliage,  and  dying  dow’n 
r/ ^  short  distance  of  the  pot,  they  retained  the  appearance 
. -1-1  in®  uiedio-fibro-tuberous.  One  feature  worthy  of  notice 
w  it  1  these  seedlings  was  that  the  leaves  were  in  a  great  many 
cases  spotted,  although  both  the  parent  plants  show’ed  no  such 
w.  By  raising  B.  coccinea  from  seeds, 
the  seedlmgs  were  marked  in  like  manner,  thus 
1  thrt  the  original  type  must  have  been  marked  in  .similar 
aid  of  splendid  illustrations  he  de.scribed  the 
nf  process  of  fertilisation,  the  ripening 
ot  seeds,  and  other  features. 
The  doctor  then  proceeded  to  deal  with  Passifloras,  a  genus 
which  has  received  considerable  attention  from  him,  and  under 
whose  cultivation  they  have  also  been  eminently  successful.  Some, 
of  the  hybrids  growing  in  his  glass  houses  at  St.  Andrews  w’ould,  if 
passed  into  commerce,  prove  remunerative ;  but  as  the  doctor 
informed  his  audience,  none  of  his  plants  have  ever  been  put  on 
the  market.  Specially  fine  was  the  variety  Margaret  Wilson,  a 
hybrid  between  P.  cserulea  and  P.  alba.  This  variety  has  been 
figured  in  “  The  Gardeners’  Chronicle,”  and  is  of  surpassing, 
excellence.  Many  other  hybrids  w’ere  depicted,  as  also  w’ere 
illustrations  to  prove  how  the  size  of  the  leaf  and  number  of. 
lobes  was  modified  by  the  parent  plants. 
Albucas  were  next  dealt  wdth,  and  the  results  obtained  by 
crossing  such  varieties  as  corymbosa,  prolifera,  Nelsoni,  &c.,. 
were  described.  Streptocarpus  hybrids  are  at  present  engaging, 
the  attention  of  Dr.  Wilson.  Tritonia  Wilsoni  is  a  rare 
plant  sent  to  the  doctor  by  his  brother,  from  South  Africa,. 
and  of  which  the  latter  has, 
perhaps,  the  only  stock  in 
Europe.  The  flower  re¬ 
sembles  the  well-known 
Tritonia  (syn.  Mont- 
bretia)  but  is  distinguished! 
by  its  lavender  colour.  Be¬ 
sides  experimenting  in 
flowers,  time  is  found  to 
give  attention  to  vegetables, 
and  fruits. 
It  is  hoped  that  by  cross¬ 
ing  Allium  Macleani,  a 
plant  introduced  from 
Cabul,  w’here  it  is  used  ex¬ 
tensively  for  salads,  with 
either  the  Onion  (Alliumi 
Cepa)  or  Leek  (Allium' 
Porrum)  to  make  it  fit  for 
culinary  purposes.  Very 
interesting  were  the  illus¬ 
trations  and  account  of  a 
hybrid  between  the  Black. 
Currant  and  Gooseberiy, 
possessing  the  appearance 
of  being  an  exact  hybrid  be¬ 
tween  the  two.  Strange  to 
say  a  plant  of  this  kind  was 
raised  by  Mr.  Burbank,  of 
America,  about  the  same 
time,  and  in  appearance 
they  are  identical,  only  Mr. 
Burbank’s  fruits  much  more 
freely.  A  lucid  account  of 
a  visit  to  the  two  eminent 
American  hybridists,  Mr. 
Burbank  and  Professor 
Hay,  brought  a  most  enjoy¬ 
able  evening  to  a  close. — 
Scotia. 
Tree  Carnations. 
Lesser  known  Hellebores. 
Ilelleborus  colcliicus  ;nia<;nificus  (rich  pur]ile);  H.  iiigcr  scoticus 
(perfectly  white). 
The  earliest  batch  of 
these  will  be  rooted,  if  not 
potted  off,  but  for  plants  to 
flower  after  next  Christmas 
propagation  may  be  done 
now.  Side  shoots,  about 
Sin  long,  form  the  best  cut¬ 
tings.  These  should  be 
taken  off  with  a  heel  and 
.  inserted  in  a  sandy  com¬ 
post  round  the  sides  of  small  pots,  and  placed  under  handlights 
in  a  temperature  of  65deg  to  70deg.  Here  they  will  root  quickly, 
and  w’lll  need  gradually  inuring  to  a  temperature  of  GOdeg  when 
rooted.  A  few  days  in  this  temperature  and  they  may  be  potted 
singly  into  thumb  pots,  using  a  compost  of  loam,  leaf  mould,  fine 
brick  rubble,  and  sand.  Following  this,  keep  them  close  in  a 
temperature  of  65deg  for  about  a  week,  syringing  them  daily, 
whcncG  they  will  soon  tako  to  tke  new  soil  and  may  be  given 
more  air,  and  lower  temperature  (GOdeg)  will  keep  them  growing 
nicely.  The  points  of  each  shoot  should  be  taken  out  when  the 
pots  are  becoming  filled  with  roots.  This  will  cause  them  to 
break,  and  form  the  foundation  of  good  plants. 
Pot  them  on  again  into  a  4in  or  4^in  sized  pot  so  soon  as  the 
new  shoots  are  making  headway.  Use  the  loam  fairly  rough 
and  pot  firm,  but  do  not  ram  it  road-hard — a  tendency  young 
men  have  in  these  days.  Keep  them  well  syringed,  and  give  air 
treely  as  the  season  advances.  These  pots  soon  will  be  filled  with' 
