596 
JRubus  Villosus. 
f  Am.  Jour.  Pharm^.. 
1      Dec,  1881. 
brown  color  externally,  and  of  a  darker  brown  in  the  intermediate- 
layer,  and  is  slightly  wrinkled.    A  longitudinal  section  of  the  bark 
shows  the  fibrous  or 
bast  tissue,  which  makes- 
it  very  tough  and. 
strong,  although  it  can 
be  torn  in  the  direction^ 
of  the  fibre  with  com- 
parative ease.  The  cross^ 
section  presents  the  me- 
dullary rays  and  t  he- 
wedge-shaped  bundles 
of  bast  tissue.  The  epi- 
phloeum  consists  of  about 
six  or  seven  layers  of 
tabular  cells,  and  the 
meditullium  is  quite 
porous  from  the  numer- 
ous ducts.  The  bark 
found  in 
BuBUS  Villosus.  Bark  of  the  root. 
Longitudinal  section,  magnified  150  diameters. 
IS 
commerce : 
peeled  from  the  inert  woody  portion. 
Rubus  villosus  is  also  interesting  from  the  fact  that  upon  the^ 
leaves  is  found  a  minute  fungus,  to  which  Schweinitz  gave  the  name 
uEcidium  nitens,  described  in  his  Synopsis  Fungorum  Carolina  Supe— 
rioris  "  as  growing  upon  the  leaves,  petioles  and  young  branches  of 
the  entire  genus.  To  the  naked  eye  its  appearance  is  that  of  an 
orange  colored  rust,  but  when  magnified  one  hundred  and  fifty  diam- 
eters it  is  found  to  consist  of  a  large  number  of  roundish  granular 
bodies,  which  appear  about  the  size  of  a  pea,  and  are  of  a  light  orange 
or  sometimes  a  deep  crimson  color.  They  are  attached  to  the  hairs^ 
and  are  found  more  plentifully  on  the  under  surface  of  the  leaves,, 
these  parts  often  becoming  so  thickly  covered  as  to  give  to  the  plant 
an  autumn  tint  or  sunburnt  appearance. 
By  cultivation  Rubus  villosus  acquires  the  habits  and  appearance  oT 
an  ornamental  shrub,  some  of  its  numerous  stamens  becoming  petals,, 
and  the  flowers  increasing  in  size ;  though  by  "  trimming  back  the 
new  growing  branches  the  amount  and  size  of  the  fruit  can  be  greatly 
increased. 
Tannin  is  the  principal  constituent  of  the  root  bark.  The  leaves- 
also  contain  this  acid  in  a  small  amount,  and  the  pleasant  acidulous, 
taste  of  the  fruit  is  due  to  the  presence  of  citric  and  malic  acids.  ^ 
