_Bromus sp._
_Artemisia tridentata_
_Chrysothamnus nauseosus_
_Purshia glandulosa_
This association is found on only the crest and desert slope of the
range between 5000 and 8000 feet elevation. There it characteristically
occupies flats and clearings in the yellow pine forest and
pinyon-juniper woodland. The dominant plant of the association is basin
sagebrush, and in many places this plant forms mixed growths with
snowbrush and _Haplopappus_. The low brush of this association is formed
by closely spaced bushes with grasses growing between.
Because of its limited occurrence in the San Gabriel Mountains, this
association there has relatively little effect on mammalian
distribution. Locally, nevertheless, the presence of this association
governs the distribution of certain mammals. For example, on Blue Ridge,
islands of sagebrush amid the conifers provide suitable habitat for
_Dipodomys agilis perplexus_ and _Perognathus californicus bernardinus_;
and in Swarthout Valley _D. a. perplexus_, _Reithrodontomys megalotis
longicaudus_, and _Lepus californicus deserticola_ are seemingly
restricted to the sagebrush flats.