DISTRIBUTION AND OCCURRENCE
SPECIES: Zuckia brandegeei | Silt Bush 



GENERAL DISTRIBUTION : 
Silt bush is mostly restricted to the Colorado River drainage in
south-central Wyoming, western Colorado, eastern Utah, northeastern
Arizona, and northwestern New Mexico [16].  The only known population
outside of the Colorado River drainage system is in the Great Basin,
just northwest of Sterling, Utah [10,16].

The chromosomal populations of silt bush reportedly differ in
geographical distribution.  Diploid populations occur mostly in
south-central Utah and northeastern Arizona [16].  Tetraploids tend to
grow in isolated populations or in more continuous bands wherever 2:1
clay substrates are exposed in northeastern Utah, south-central Wyoming,
eastern Colorado, and northwestern New Mexico [(Pendleton, pers. comm.
1987), 16].


ECOSYSTEMS : 
   FRES30  Desert shrub
   FRES34  Chaparral - mountain shrub
   FRES35  Pinyon - juniper
   FRES40  Desert grasslands


STATES : 
     AZ  CO  NM  UT  WY


ADMINISTRATIVE UNITS : 
     ARCH  CANY  CARE  COLM  DINO  GLCA
     NABR  PEFO


BLM PHYSIOGRAPHIC REGIONS : 
    7  Lower Basin and Range
   10  Wyoming Basin
   11  Southern Rocky Mountains
   12  Colorado Plateau


KUCHLER PLANT ASSOCIATIONS : 
   K023  Juniper - pinyon woodland
   K031  Oak - juniper woodland
   K037  Mountain-mahogany - oak scrub
   K039  Blackbrush
   K040  Saltbush - greasewood
   K053  Gramma - galleta steppe


SAF COVER TYPES : 
   239  Pinyon - juniper


SRM (RANGELAND) COVER TYPES : 
   212  Blackbush
   315  Big sagebrush-Idaho fescue
   401  Basin big sagebrush
   414  Salt desert shrub


HABITAT TYPES AND PLANT COMMUNITIES : 
Silt bush can be found growing near Stansbury cliffrose (Purshia
mexicana var. stansburiana) communities, pinyon-juniper and juniper-oak
woodlands, and salt desert shrublands [2,9,10,11].  Where silt bush
grows with other species it is more commonly found in saltbush
communities that are in a very early seral stage [Pendleton pers. comm.,
1987].  It may also occur as a pioneer plant restricted by competition
to steep 2:1 clay slopes where other plants cannot survive [Pendleton
pers. comm., 1987].

Related categories for Species: Zuckia brandegeei | Silt Bush