392  Rhamnus  Purshiana.  {^S^dS^mA 
place,  this  will  be  ready  for  cutting  in  a  few  years,  the  other  branches 
in  the  meantime  having  been  treated  in  the  same  way. 
Seed  of  Rhamnus  Purshiana  is  not  on  the  market,  but  would 
have  to  be  collected  by  some  one  in  the  cascara  region.  (Alice  Henkel, 
"  The  Cultivation  of  Medicinal  Plants,"  The  Druggists'  Circular, 
March,  1912,  p.  133.) 
The  following  is  a  description  of  the  bark,  leaves,  flowers,  and  nut- 
lets of  Rhamnus  Purshiana  by  Sargent  ("  Silva  of  North  America," 
vol.  2,  pp.  37-40). 
The  bark  of  the  trunk,  even  on  old  trees,  is  rarely  more  than  a 
quarter  of  an  inch  thick,  and  varies  in  color  from  dark  brown  to 
light  brown  or  gray  tinged  with  red,  the  surface  being  broken  into 
short,  thin  scales.  The  branchlets,  when  they  first  appear,  are 
coated  with  fine,  soft  pubescence;  they  are  pale  yellow,  green,  or 
reddish-brown,  and  are  pubescent,  glabrous,  or  covered  with  scat- 
tered hairs  in  their  second  season,  when  they  are  marked  with  large, 
elevated  scars  left  by  the  falling  of  the  leaves. 
The  leaves  are  alternate,  elliptical-oblong,  obovate,  acuminate,  or 
broadly  elliptical,  and  are  obtuse,  acute,  or  bluntly  pointed  at  the 
apex,  rounded  sub-cordate,  or  sometimes  wedge  shaped  at  the  base, 
and  serrulate,  denticulate,  obscurely  crenate,  or  often  merely  entire 
with  wavy  margins.  They  are  thin  membranaceous  or  sometimes 
thick  and  coriaceous,  and  are  glabrous  or  pubescent  with  scattered 
hair  on  the  lower  surface  and  along  the  veins  on  the  upper  surface. 
They  vary  from  an  inch  to  over  seven  inches  in  length,  and  are  con- 
spicuously netted  veined,  with  broad  and  prominent  mid-ribs  and 
primary  veins  ;  they  are  borne  on  stout,  often  pubescent,  petioles 
one-half  inch  or  an  inch  long,  and  are  sometimes  pale  yellow-green 
above  and  below,  and  sometimes  dark  green  and  rather  opaque 
above  and  paler  and  often  somewhat  orange  color  or  brown  on  the 
lower  surface. 
In  Washington  and  Oregon  and  at  high  elevations  in  the  moun- 
tains the  leaves  fall  late  in  November,  having  previously  turned 
pale  yellow.  Farther  south  and  near  the  California  coast  they  re- 
main on  the  branches  almost  all  winter,  or  until  the  following 
spring.  The  stipules  are  membranaceous,  acuminate,  and  nearly 
deciduous. 
The  flowers  are  produced  on  the  young  shoots  in  axillary  um- 
bellate cymes  or  slender,  pubescent  peduncles  varying  from  one- 
half  to  nearly  an  inch  in  length.   The  pedicels  are  slender,  pubescent, 
