544 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER 
June  11,  1896 
all  are  not  equally  fine  or  desirable  for  gardens,  as  some  are  of  doubtful 
hardiness,  and  others  far  from  showy. 
C.  scoparius  Andieanus,  although  only  a  variety  of  the  common 
Broom  and  a  wildling  discovered  recently  in  France,  is  one  of  the  most 
striking  and  handsome  of  early  summer  flowering  shrubs.  Its  charming 
appearance  is  due  to  the  al se  or  wings  of  the  flower  having  a  rich  golden 
brown  blotch,  which  forms  a  beautiful  contrast  with  the  bright  yellow 
of  the  other  parts  of  the  flower.  The  plant  is  as  free  growing  and  hardy 
as  the  common  Broom,  both  of  which  prefer  a  calcareous,  gravelly,  or 
well-drained  soil,  and  open,  yet  preferably  sheltered  situation.  This, 
planted  in  masses,  is  one  of  the  finest  and  most  striking  of  shrubs.  It 
commences  to  flower  when  in  a  young  state,  and  may  be  grown  success¬ 
fully  in  pots. 
C.  albus,  or  White  Broom,  is  not  so  hardy  nor  so  showy  as  C.  8.  An- 
dreanus,  but  its  long  racemes  of  small  white  flowers  disposed  on  the 
slender  graceful  shoots  have  a  fine  effect.  It  also  flowers  freely  in  a 
young  state,  and  by  itself,  in  a  mass,  or  associated  with  C.  s.  Andreanus 
and  the  common  Broom,  has  a  very  attractive  appearance.  Massing 
brings  the  species  out  in  their  most  striking  features.  C.  albus  is  a 
native  of  Spain  and  Portugal.  The  trio  attain  to  a  height  of  3  to  10  feet, 
but  are  best  kept  at  from  3  to  6  feet  by  cutting  out  the  old  growths  to 
some  extent,  or  by  thinning  and  encouraging  young  from  tbe  base. 
C.  capitatus,  or  headed  flowered,  is  best  seen  as  a  low  standard,  its 
fine  rich  yellow  flowers  having  a  fine  effect  in  the  early  summer.  The 
head,  even  in  good  specimen,  does  not  exceed  that  of  a  standard  Rose. 
It  requires  a  calcareous  gravelly  soil,  otherwise  it  cannot  be  depended 
on  for  hardiness.  Native  of  Italy. 
C.  purpureus  produces  purple  flowers  on  short  peduncles,  and  of  pro¬ 
cumbent  growth,  but  twiggy.  This  is  best  grown  as  a  standard,  having 
a  better  effect,  and  when  in  flower  is  very  beautiful.  There  is  a  white 
variety. 
C.  elongatus  is  another  of  the  low  forms  that  are  seen  at  the  best  as 
a  standard,  the  yellow  flowers  having  a  fine  effect.  It  is  a  native  of 
Hungary. 
C.  hirsutus  has  yellow  flowers  on  very  short  peduncles,  and  forms  a 
fine  compact  head  as  a  standard.  All  the  species  or  varieties  named 
deserve  a  place  in  every  garden,  however  small. — G. 
BLACK  STRIPE  IN  TOMATOES. 
Referring  to  the  reply  given  to  “W.  L.  H.”  (page  527), 
“  black  stripe  ”  is  caused  by  the  entrance  into  and  growth  of  the 
mycelial  hypbte  of  a  fungus  within  a  Tomato  plant.  The  growth 
entering  the  Tomato  plant  is  the  pro-mycelium  of  the  fungus 
named  Hypomyces  solani.  This  pro-mycelium  or  first  growth 
from  the  resting  spore  or  body  named  enters  the  plant  by  piercing 
the  radicle  (root  stem)  or  lateral  (fibry  roots),  and  ascends  (for  itB 
work  is  “upwards  and  onwards”)  the  stem  by  the  woody  fibre, 
abstracting  the  contents  of  the  cells  and  giving  them  a  brown 
appearance,  which  is  readily  seen  when  the  stem  of  a  diseased  plant 
is  cut  through.  Plants  so  attacked  become  arrested  in  growth,  and 
thus  abide  for  some  time,  hence  the  term  “sleepy  disease.”  But 
this  does  not  last  long,  for  sometimes  the  mycelial  hypbse  encircles 
the  woody  tissue  and  cuts  off  the  ascent  of  the  sap,  and  the  young 
growths  droop  and  die. 
In  case  the  stem  be  not  girdled  the  mycelial  hyphac  continues 
its  development  upward  in  the  stem  of  the  attacked  plant,  and 
ultimately  a  stripe  or  stripes  of  discolouration  appear  on  the  skin 
of  the  young  fruit,  usually  at  the  eye,  and  sometimes  on  the  stem 
of  the  plant.  Such  stripe  or  stripes  become  brown,  and  after¬ 
wards  dark  coloured  or  black.  From  this  surface  or  destroyed 
tissue  spring  the  outgrowths  or  erect  hypbas  of  the  fungus  bearing 
the  first  or  conidial  reproductive  bodies,  the  stage  of  the  plant 
named  by  botanists  Diplocladium  solani. 
The  conidia  or  first  spores  are  carried  hither  and  thither  by  the 
least  puff  of  air,  and  alighting  on  any  dead  vegetable  matter,  or 
even  on  soil  largely  suffused  with  vegetable  matter  in  solution,  the 
conditions  being  favourable  for  development,  they  germinate,  and 
by  growth  of  mycelial  hypbre,  which  is  built  up  of  the  dead  organic 
matter,  permeate  the  decaying  plant  or  soil  containing  the  vegetable 
substance,  and  from  this  springs  the  form  of  outgrowths  constituting 
the  plant  named  Fusarium  solani  (fig.  91,  B,  top  left  hand  corner  of 
the  illustration).  This,  by  the  dissemination  of  its  spores,  gives 
rise  to  its  like  form  on  any  Tomato  plant  that  afford  favourable 
conditions  of  soil  (host)  and  environment  (climate)  for  develop¬ 
ment. 
Opinion  is  divided  as  to  whether  the  Fusarium  is  saprophytic  or 
parasitic,  some  contending  that  the  plant  or  part  was  in  a  state  of 
decay  when  attacked,  and  others  as  positively  affirm  that  it  assails 
living  tissue,  and  the  decay  set  up  is  a  consequence  of  its  growth. 
Fusarium  solani,  however,  is  an  endophytic  fungus,  and  if  the 
germinal  tube  from  one  of  its  spores  enters  a  Tomato  plant,  it  may 
be  by  a  wound  or  other  cause  of  dead  tissue,  the  mycelial  hypbse  is 
not  content  with  the  dead  organic  matter,  but  by  the  growth  of  the 
mycelial  hyphse  and  consequent  contact  of  the  ferment  it  sets  up 
with  the  living  tissues  these  are  destroyed,  and  thus  the  Fusarium 
is  decisively  a  parasite. 
Albeit,  the  Fusarium  outgrowths  or  reproductive  bodies  never 
spring  from  the  living  parts  of  the  infested  plant,  beiDg  always 
confined  to  the  dead  or  putrefying  tissues,  yet  its  hypbse  and  out¬ 
growths  are  constructed  solely  and  absolutely  out  of  the  organic 
substance  of  the  infested  plant,  whether  that  part  be  living  or  dead 
— first,  the  mycelial  hypbas  on  the  living  or  freshly  destroyed  cell 
contents,  and  afterwards  the  aerial  hypbse  bearing  the  reproductive 
bodies. 
Within  the  dead  tissue  of  a  plant  infested  by  Fusarium  solani, 
and  even  in  soil  containing  sufficient  dead  organic  matter  to  sustain 
Diplocladium  solani,  and  the  secondaiy  form  of  this  particular 
fungus — namely,  F.  solani,  certain  parts  of  the  mycelial  hypbae 
become  swollen,  and  form  roundish  oval  bodies  (fig.  92,  F,  x,  y ), 
which  are  the  final  or  resting  stage  of  the  fungus  Hypomyces 
solani,  and  are  practically  frost-proof,  water-proof,  and  drought- 
proof,  therefore  may  abide  in  the  soil  indefinitely  without  impair¬ 
ment  of  vitality. 
By  these  so-called  resting  spores  this  peculiar  vegetable 
organism  continues  from  season  to  season,  and  in  no  other  way 
can  Tomato  plants  become  infested  by  “drooping,”  “sleepy,”  or 
“  black  stripe  ”  disease,  but  by  the  soil  or  the  seed,  and  that  in 
consequence  of  the  one  or  the  other  containing  such  spore 
(Hypomyces  solani),  and  the  pro-mycelium  from  it  entering  the 
FIG  fll .  —  SECTIONS  OF  POTATO  OR  TOMATO  TISSUE  AFFECTED 
WITH  FUNGI. 
A,  tissue  affected  with  curl  fungus  (Maerosporium  commune  var.  solani) :  a,  mycelial 
hyphm  ;  6,  haustoria  in  invaded  cells ;  c,  perfect  cells ;  d,  cell  wall  (cellulose)  ; 
e,  protoplasm  ; /,  starch  grains;  g,  nucleus;  h,  epidermal  cells;  i,  stoma  ;  j,  coni- 
diophores  of  curl  fungus;  k,  gland;  l,  simple  hair ;  to,  jointed  hairs.  B,  dry  or 
wet  rot  fungus  (Fusarium  solani);  n,  mycelial  hyphee  ;  o,  outgrowths ;  p,  coni- 
diophores ;  q ,  conidia  ;  r,  spore. 
root-stem  or  roots  of  the  developing  Tomato  plant.  Thus  “black 
stripe,”  an  exceedingly  vague  term,  has  a  very  simple  life  history. 
1,  The  fungus  Hypomyces  solani  gives  rise  of  itself  (fig  92,  F,s  3), 
or  by  parasitism  (a  2)  to  Diplocladium  solani  (D).  2,  Fusarium 
solani  ( E )  follows  in  infested  tissue.  3,  Hypomyces  solani  is  the 
final,  or  resting  stage  (jF,  *,  ?/).  The  Diploclodium  conidia  can 
only  vegetate  on  moist  decaying  vegetation,  or  on  soil  containing 
putrefying  organic  matter,  or  »uch  luffusing  the  stratum. 
Fusarium  may  follow,  and  its  conidia,  or  spores,  give  rise  to 
Potato  or  Tomato  rot,  or  this  stage  may  be  purely  saprophytic,  also 
that  of  the  final,  or  Hypomyces.  In  presence,  however,  of  a 
Potato  or  Tomato  plant,  the  pro-mycelium  of  the  Hypomyces  may 
enter  the  root-stem  or  roots,  and  ascending  the  stem  content 
itself  by  not  mounting  above  ground  level,  as  shown  in  fig.  92, 
C  at  s.  This  is  a  common  occurrence  both  with  the  Potato  and 
Tomato,  and  is  an  exact  counterpart  of  what  “W.  K.”  describes 
on  page  515. 
For  some  reason  or  other  the  mycelial  hypbse  becomes  arrested* 
but  the  plant  being  girdled  it  dies,  unless  soil  is  placed  about 
the  stem,  so  that  roots  may  be  emitted  from  the  base  of  the  living 
part,  which  is  done  by  some  growers,  and  the  plants  afterwards 
produce  good  crops  of  perfectly  clean  fruit  or  free  from  “  black 
stripe.” 
Much  “black  stripe,”  however,  is  “sudden  collapse  ’’fungus 
