VALUE AND USE
SPECIES: Rhamnus purshiana | Cascara 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Cascara is a wide-spread but not abundant shrub found primarily in
forested mountains [27].  It has been listed as a browse species for
mule deer in Oregon [7,29] and for elk in northern Idaho [26].  Cascara
was found to be a winter browse species for mule deer in northwestern
Oregon.  Sixty-eight percent of available cascara shrubs were browsed
during the winter.  In summer, however, cascara was less desirable; only
27 percent of available cascara shrubs were browsed [6].  Other mammals
that browse cascara include the Olympic black bear, Oregon gray fox,
racoon, and ring-tailed cat [1,29].  Cascara drupes are eaten by five
species of birds including the Oregon ruffed grouse and band-tailed
pigeon.  Cascara is of no value as forage for livestock [30].  How the
purgative characteristics of cascara bark and drupes affect wildlife are
not known [29].


PALATABILITY : 
Although utilized by wildlife, cascara is not very palatable.  Cascara
is browsed very lightly by sheep and to some extent by mule deer, but
for all practical purposes its forage value is negligible [27].
Palatability of cascara leaves to elk on the Selway Game Preserve, Idaho
was poor [30].

The relish and degree of use shown by wildlife species for cascara in
British Columbia are as follows [4]:

     Specie            Palatability
-----------------      ------------
bighorn sheep             poor
elk                       fair
moose                     poor
mule deer                 poor
white-tailed deer         poor
caribou                   poor
coast deer                good


NUTRITIONAL VALUE : 
The nutritive value of cascara is poorly understood.  Cascara was found
to be nitrogen-rich in one southern British Columbia study [14].


COVER VALUE : 
Cascara often forms brushy stands capable of providing abundant thermal
and hiding cover [2].  The shrubby form may prove a more valuable cover
species than the treelike northern form [29].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
NO-ENTRY


OTHER USES AND VALUES : 
The greatest known value of cascara is its purgative properties.  In a
single year, five million pounds of dried cascara bark from the Pacific
Northwest was processed by pharmaceutical companies in the manufacture
of laxatives [1,23].

The Kootenai and Flathead tribes of western Montana used cascara as a
laxative, consuming it in the form of a tea brewed from the bark.  These
Indians believed that it would be a purgative when the bark was stripped
downward.  If stripped upward, the drug would act as an emetic.  Cascara
bark contains anthraquinare derivatives, tannin, resins, starch,
glucose, and other compounds [11].  When the bark is chewed, it tastes 
extremely bitter, and may temporarily numb the taste buds [1].  

The flesh of some animals which have consumed the drupes is said to
retain some of the purgative properties.  The juice pressed from the
berries is used to prepare a 'syrup of cascara'.  The bark and dried
berries have been used as a source of yellow- and saffron-colored dyes.
The berry juice. when combined with alum, produces a green dye once used
by artists [21].

Apparently, if cascara is handled for a long time, the laxatative
effects can even be transferred through the skin [1].  For maximum
effectiveness, bark collection is recommended from mid-April to the end
of August, and bark should be stored as long as possible before being
used [11].


MANAGEMENT CONSIDERATIONS : 
Disease:  Cascara has been found to be susceptible to laboratory
exposures of crown rusts [29].

Herbicides:  Garlon 4 and Tordon 101 applied during early foliar
development top-killed 95 percent of cascara 3 years after treatment
[19].

Related categories for Species: Rhamnus purshiana | Cascara