The  manner  of  association  of  these  three  Rhizophoras  is  of


XXX  RHIZOPHORA  443

interest  in  connection  with  the  origin  of  the  seedless  Selala.  They
very  rarely  occur  mingled  together,  but  grow  gregariously  in  con-
tiguous colonies  ;  and  not  uncommonly  all  three  may  occur  on  the
same  line  of  coast  within  a  distance  of  a  few  hundred  yards.  The
colonies  pass  into  each  other  without  a  break,  and  there  is  no  fixed
rule  of  association.  Whilst  on  the  south  side  of  Vanua  Levu  the
Selala  is  generally  associated  with  the  American  Rhizophora,  on
the  north  side  it  is  usually  in  touch  with  the  Asiatic  species.  In
other  localities  all  three  occur  in  contiguous  colonies.  The  Selala
colony  may  be  exposed  on  the  line  of  a  river-bank  or  along  the
sea-coast,  or  it  may  lie  in  the  heart  of  an  extensive  mangrove  tract
The  most  extensive  mangrove  region  in  Fiji,  that  of  the  Rewa  delta,
is  in  great  part  occupied  by  Rhizophora  mangle  ;  but  all  three  forms
grow  together  in  the  eastern  part  of  the  delta  ;  and  here,  strangely
enough,  as  at  Daku,  the  Selala  may  grow  sporadically,  and  all  three
may  grow  mixed  together  with  their  branches  intercrossing.
Tlie  Characters  of  the  Selala  or  Seedless  Rhizopfiora  compared
with  those  of  the  American  Mangrove  {R.  mangle)  and  the
Asiatic  Mangrove  {R.  mucronata).
