360 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER, 
April  28,  1961. 
Notes  on  Irises. 
Iris  Haynei. 
During  the  past  three  or  four  weeks  notes  have  appeared  in 
the  gardening  papers  briefly  describing  this  new  Cushion  Iris 
from  Palestine,  and  which"  has  been  twice  certificated  when 
staged  by  Me.ssrs.  Cutbu.sh  and  Sons,  of  Highgate.  It  was 
certificatkl  at  the  Royal  Botanic  Society’s  first  exhibition,  and 
again  at  the  Royal  Horticultural  Society’s  meeting  on  April 
19.  Our  illustration  shons  a  flower  considerably  reduced. 
The  magnificent,  silky-looking  flowers  measure  Gin  from  the  tips 
of  the  .standards  to  the  tips  of  the  falls.  The  standards  are  blue- 
purple  and  grey  in  various  shades.  The  falls  measure  3in 
across,  and  are  deep  brown  at  the  margins,  with  an  intense, 
glistening,  satiny  spot  in  the  centre,  this  being  a  feature  of 
beauty  and  distinctiveness.  “  Compared  with  others,  it  has  the 
falls  of  I.  sofarana  and  the  standards  and  habit  of  I.  atrofnsca.” 
These  Oncocyclus  Irises  are  difficult  to  cultivate  to  success. 
Iris  tubeposa,  “The  Widow.” 
In  the  cpiaint  little  Iris  tnberosa  we  have  an  example  of  the 
many  plants  which  supply  ample  fields  of  discussion  for  the 
botanists,  and  which,  in  consequence  of  the  disputes  of  these 
scientists,  give  great  trouble  to  the  fraternity  of  gardeners.  It 
is  not  at  ail  pleasant  to  be  told  that  the  plant  we  have  long 
knoAvn  as  so-and-so  is  now  something  else.  Iris  tnberosa,  how¬ 
ever,  is  a  plant  upon  which  differences  of  opinion  are  inevitable, 
for  it  is  not  only  doubted  whether  it  is  an  Iris  or  something 
else,  but  even  to  those  who  are  certain  that  it  is  an  Iris  it 
presents  another  problem,  and  this  is,  whether  it  is  a  bulbous 
or  a  tuberous  Iris.  The  truth  appears  to  be  that  it  is  both  ; 
for,  as  Sir  M.  Foster  says,  “  It  is  a  bulb  when  a  baby,  and 
becomes  a  tuber  as  it  grows  old!  ”  These  matters  are,  how¬ 
ever,  of  less  interest  to  ns  than  its  qualities  as  a  garden  plant, 
but  here,  again,  we  are  upon  debatable  ground. 
Iris  tnberosa,  as  might  indeed  be  gathered  from  its  popular 
name  in  some  parts — The  \\hdow — is  not  a  brilliant  flower,  yet 
there  is  something  attractive  about  its  quietly-coloured  flowers. 
The  blade  of  the  fall  of  the  flowers  is  of  a  deep  velvety  black 
or  black  purple,  and  the  ground  colour  is  of  an  olive  green, 
while  the  rest  of  the  flower  is  of  a  greenish-yellow,  with  a  com¬ 
bination  of  lighter  streaks  and  shadings.  A  high  authority  on 
matters  of  taste  says  that  I.  tnberosa  in  its  colouring  is  espe¬ 
cially  charming,  and  this  is  an  opinion  which  those  who  have 
studied  it  will  endorse.  ,Yet  the  ordinary  looker-on  will  think 
it  dull  and  deficient  in  brightness.  Its  leaf  is  rather  like  that 
of  the  more  lovely  I.  reticulata,  while  the  tuber,  when  at  full 
size,  is  as  an  authority  remarks,  like  that  of  a  deformed  Potato. 
In  fact,  there  is  about  the  whole  plant  an  anomalous  character 
which  puzzles  many.  It  seems  wonderfully  little  known,  and 
I  have  frequently  had  plants  sent  to  me  to  name. 
These  were,  however,  principally  from  the  south  of  our 
islands,  and  this  is  just  what  one  may  expect,  seeing  that  it  is 
not  a  certain  bloomer,  and  likes  a  warm  place  and  a  calcareous 
soil.  Its  leaves  are  often  injured  by  spring  frosts,  and  some 
have  recommended  that  it  should  be  lifted  and  replanted 
annually.  This  is  not  always  satisfactory,  and  one  had  better 
leave  it  in  the  ground  all  winter  and  summer  and  take  rue 
risk.  It  is  a  verv  old  plant  in  gardens,  having  been  the  “  Velvet 
Flowei’-de-Luce  of  Parkinson,  and  the  other  genus  to  which 
it  has  been  attributed  by  botanists  is  that  of  the  Hermodactylns. 
It  is  widely  spread  over  the  continent  of  Europe,  and  is  a 
doubtful  native  of  England  and  Ireland. — S.  Arnott. 
The  Resting  oi  Plants  under  Cnltivation. 
( Continued  from  page  337.) 
Tubers  and  Bulbs. 
The  name  tuber  is  given  to  any  swollen  part  of  a  plant  in 
which  re.servcs  are  stored  up,  except  bulbs  and  leaves.  Thus,  it 
may  be  of  stem  nature,  as  in  the  case  of  the  Potato  and  Arti¬ 
choke,  Dioscorea,  and  epiphytic  orchids,  or  of  root  nature,  as  in 
Dahlia  and  our  common  British  orchids ;  and  we  not  only  look 
upon  them  as  a  means  of  carrying  the  plant  through  the  resting 
season,  but  also  as  a  means  of  vegetative  reproduction.  The 
bulb  proper  is  a  modified  shoot,  consisting  of  a  disc-like  stem 
at  the  base,  bearing  a  more  or  less  spherical  mass  of  closely 
folded  leaves  above,  which  are  swollen  with  reserves. 
Now,  we  see  that  such  plants  possess  these  special  means  of 
carrying  them  through  a  dry  season  without  injury  in  their 
native  homes,  and  ivithont  that  re.st,  under  cnltivation  they  do 
not  tend  to  make  good  growth  or  to  flower  satisfactorily  ;  and 
on  the  other  hand,  if  we  give  them  a  too  severe  period  of  rest, 
the  tubers  or  bulbs  lose  a  good  deal  of  their  substance,  and  are 
consequentlv  weakened.  In  some  case  the  roots  are  more  or 
less  active  during  the  resting  season,  and  of  course  these  should 
not  be  too  severely  dried  in  the  soil,  or  left  for  any  length  of 
time  before  being  potted  when  imported. 
If  we  study  their  structure,  we  can  see  that  they  do  not  all 
possess  the  same  amount  of  substance,  and  that  they  do  not 
all  grow  under  the  same  conditions  in  Nature,  so  we  must  use 
our  judgment  as  to  what  is  best  for  them,  and  if  general  treat¬ 
ment  is  not  suitable,  we  must  classify  them  a  little,  and  rest 
each  group  accordingly.  Most  of  our  bulbous  plants  flower 
after  their  period  of  rest  has  come  to  an  end,  and  in  most  cases 
this  should  be  a  reminder  that  it  is  time  to  comnience  giving 
them  water,  to  be  gradually  increased  as  the  foliage  appears, 
that  as  much  strength  as  possible  may  be  got  into  the  leaves 
and  bulbs.  Water  is  to  be  gradually  dimiifished  as  the  growing 
season  comes  to  an  end,  and  ventilation  and  light  increased, 
until  the  foliage  has  died  away  in  some  cases,  and  in  others 
(which  do  not  lose  their  foliage)  to  a  point  where  common-sense 
tells  ns  by  their  appeaiance  we  have  gone  far  enough  in  the 
drying  off  process. 
In  these  few  observations  on  the  growing  season,  I  have  per¬ 
haps  strayed  from  the  title  of  my  subject,  but  this  I  found 
necessary  in  order  to  point  out  the_  inportance  of  gradually 
preparing  our  plants  for  the  rest  which  is  so  necessary  to  their 
welfare.  The  temperature  of  the  surroundings  of  bulbous  plants 
when  at  rest  is  important.  Those  tender  ones  which  rest  during 
our  summer  will  not  take  any  harm  from  sun  heat  providing 
they  have  plenty  of  ventilation,  but  most  of  them  rest  during 
our  winter,  and  have  to  be  stored  away  in  sheds  or  under  the 
stages  of  our  plant  houses  (if  we  are  not  fortunate  enough  to 
have  a  place  specially  for  them).  Under  these  conditions,  care 
should  be  taken  that  they  are  not  placed  too  close  to  the  hot- 
water  pipes.  I  know  thel'e  are  exceptions,  where  they  require 
a  very  severe  drying  before  they  will  flower,  but  the  majority 
will  rest  well  in  a  temperature  of  55deg  Fahr.  if  they  be  tropical 
ones,  or  lodeg  lower  for  those  which  make  their  growth  in  a 
cool  house,  providing  they  are  kept  quite  dry. 
We  have  to  remember  that  the  conditions  of  pot  culture  are 
somewhat  different  to  the  natural  conditions.  The  small 
amount  of  soil  contained  in  a  pot  soon  becomes  dried  through, 
and  if  they  are  stored  in  too  high  a  temperature  the  cultivator 
has  to  water  them  to  keep  them  from  shrivelling  too  much, 
and  then  growth  will  commence  prematurely,  and  piobably  no 
flower  is  the  result.  These  remarks  are  chiefly  directed  to  such 
plants  as  Crinums,  Hiemanthus,  Arisannas,  Aclnmenes,  and 
Begonias,  and  Gloriosas,  and  the  Zingiberaceso.  Such  bulbous 
plants  as  the  Ixias,  Freesias,  Lachenalias,  and  N erines,  which 
rest  during  our  summer,  should  be  gradually  dried  off  afte 
flowering,  and  ultimately  placed  in  a  cold  frame  wheie  th^  get 
full  benefit  from  sunshine  and  air,  and  protection  from  heay 
rains  Manv  of  the  tender  bulbs  and  tubers  start  into 
growth  at  a  time  suitable  to  our  convenience  or  requirements 
if  we  want  them  earlier  than  usual,  but  in  a  collection  we  fi 
there  are  some  which  we  cannot  prevent  from  staiting  into 
growth  after  a  certain  period  even  though  keep  Emm  in  a 
cool  place  and  quite  dry.  I  have  noticed  this  with  many 
Arismmas,  Hmmanthus,  and  such  tubers 
it  seems  strange  that,  although  they  are  still  kept  -undei  tlm 
coSns  in  .“uch  they  rested  so  tvell,  ‘ er 
wm-k  over  which  we  have  no  control,  this  innuence  is  eiyie 
?ve'h‘a'™  rtrr  fSi  s  rova„rt^o 
tivP  them  plenty  of  light,  or  the  constitution  of  the  plant 
? '  r  a„d%f  iS 
ally  sVep  attention 
“s'  pT,?a^a'3i't“o.“Xc,f  polls  more  to  '(he  restmg  season. 
because  <l'>™S„(Sr®''°lSs  *tingTa'S  "!s““^  those  tvhich 
Jeldonf  flower  exce^  it  has  had  a  good  long  season  of  lost  by 
being  kept  quite  dry,  but  requires  plenty  of  water  when  making 
A  Tood  manv  ferns  possess  fleshy  rhizomes,  especially  the 
accord’  The  great  majority  of  ferns  rest  by  the 
temperature  and  the  shortening  of  the 
should  have'  sufficient  water  at  the  roots  to  keep  the  foliage 
healthy.— E.  J.  Allard,  Cambridge  Botanic  Gardens. 
(To  be  concluded.) 
