IMPORTANT WESTERN BROWSE PLANTS 3 
Great Basin region 
Sage-greasewood formation. 
River bottom-meadow formaiion. 
Arizona-New Mezico district 
Desert-plain formation. 
Dune formation (New Mexico). 
Bolson-basins formation. 
Lava-beds formation. 
Coleogyne (blackbrush) formation. 
Pinion formation. 
Mohave district 
Covillea (creosote bush) formation. 
Salvia (true sage)-Ceanothus association, in the pifon-juniper formation. 
Columbian region 
Salal formation. 
Silver sage formation. 
Ledum-bog formation. 
Californian region 
Dune formation (bearberry, shrub lupine, etc.). . 
White ash plain formation. 
Bog formation. 
Redwood slopes and flats formation (containing a copious association of shrubs 
as an understory). 
Chaparral formation. 
San Joaquin district 
River-bank formation. 
Sierra area 
Foothill formation (chaparral). 
Coastal territory 
Chaparral formation. 
1. Mountain facies. 
2. Foothill facies. 
Cafion formation. 
San Jacinto territory : 
Mesa formation. 
Chaparral formation. 
Alpine formation. 
Clements (20) recognizes 20 climax plant formations on the North 
American Continent, of which 6 are represented by western shrubs. 
These are: 
Foothill chaparral: Ceanothus-Quercus-dryon. 
Desert chaparral: Prosopis-Covillea-eremion. 
Thorn scrub: Cereus-Fouquieria-eremion. 
Desert scrub: Atriplex-Artemisia-halion. 
Arctalpine scrub: Betula-Saliz-helion. 
Heath: Ledum-Vaccinium-ozryon. 
While not, of course, of forage value equal to the grasses, browse 
is of enormous importance to the livestock industry under western 
range conditions, and especially in times of drought and other 
occasions of feed shortage. Roughly speaking, of the browse 
species so far collected on national-forest ranges, only about 1 in 
18, or 5.5 per cent, possesses very considerable forage value, but the 
number that are grazed to some extent, at least under certain cir- 
cumstances, is very great. Only about 30 species of these shrubs, 
or 3.15 per cent, appear to have been poisonous to livestock, but a 
