AGRICULTURAL  BULLETIN 
OF  THE 
STRAITS 
AND 
FEDERATED  xM  A L A Y STATES. 
No.  3.]  MARCH.  1903.  [VoL.  II. 
JELUTONG  (Dyera  Costulata). 
Pf.ATES  III  & IV. 
The  Jelutong  tree  Dyera  Costulata  is  one  of  the  biggest  tree  of 
the  Malay  Peninsula,  attaining  a height  of  over  two  hundred  feet. 
It  belongs  to  the  order  Apocynacece  and  is  allied  to  A/sfonia,  The 
stem  is  covered  with  grey  bark,  and  is  straight  and  cylindric, 
remarkable  for  having  no  buttresses,  a very  unusual  circumstance 
in  a tree  attaining  so  great  a size.  Unlike  most  of  our  gigantic 
trees  also,  it  retains  its  lower  branches  for  a long  time  so  that  the 
form  of  the  tree  is  more  or  less  cone-shaped.  The  leaves  are 
whorled  at  the  ends  of  the  branches,  rather  leatherv  dark  dull 
green  ab(jve  and  glaucous  beneath,  oblong  blunt  or  occasionallv 
subacute  at  the  top,  with  a broad  base,  the  edges  waved,  nerves 
very  prominent  beneath  about  15  pairs,  length  6 to  8 inches  loner 
2 to  3^  inches  wide,  petiole  bright  green  thick  2 inches  long.  The 
dowers  are  produced  once  a year  in  March  or  earlier  in  lax  co- 
rymbs, about  5 inches  long,  in  the  axils  of  the  leaves.  They  are 
whorled  or  tufted  at  the  ends  of  the  pedicels,  white,  ^ inch  lono-. 
The  calyx  tubular  short.  1 he  corolla  tube  is  short  much  shorter 
than  the  five  oblong  obtuse  lobes  which  have  the  characteristic 
twist  of  the  Apocynaceae.  d'he  stamens  are  five  in  number  biio-ht 
brown,  anthers  conic  blunt  on  a very  short  thick  filament.  Pistil 
conic.  The  fruit  is  a very  large  pair  of  deflexed  woody  pods  10  to 
14  inches  long  sub-cylindric  at  first  but  si  ightly  narrowed  to  both 
ends,  brown.  Thr-y  split  longitudinally  for  their  whole  length,  on 
the  outer  edge  showing  a broad  inner  flange  on  each  margin.  'Phe 
seeds  are  very  thin  and  flat  nearly  an  inch  long,  furnished  at  each 
end  with  a thin  papery  wing,  making  the  whole  oblong  in  outline, 
and  2h  inches  long  and  J inch  wide. 
Before  flowering  the  Jelutong  sheds  its  leaves  and  becomes 
nearly  bare  for  a day  or  so  after  which  the  buds  appear  and  it  is 
soon  covered  with  leaves  again. 
'fhree  species  of  Dyera  have  been  described,  D.  laxifiora, 
1 look..  111.  and  D.  Costulata,  Hook.,  hi.  both  from  the  Malay  I^enin- 
sula,  but  1 do  not  think  that  these  two  species  are  distinct  and 
Dyera  Loivii  from  Iforneo,  'Phis  latter  is  distinguished  by  its 
