358 BOTANICAL GAZETTE [NOVEMBER 
Associations generally intermediate or established in character (usually sub- 
ase to primitive associations, but often in habitats apparently little 
ed from the primitive condition); soil often of mixed or fine texture, 
or PRT considerable humus content; vegetation usually less open and sparse 
than in precedin 
Typically developed in ean or semi-xerophytic habitats, which are of 
general occurrence in the foothills region (these associations are conse- 
quently extensive) 
ominant plants evergreen trees; usually in rocky or coarse soil 
Of Seeae an = xerophytic ueneters ee distributed in the 
OOUHINS TOMI iso pck Bui ed a FUSES ws a e's ock pine association 
Of Selativey | more xerophytic pharactess of ae Rite (east of the 
range-crest) more southerly distribution than preceding 
Pinyon-cedar association 
Dominant plants deciduous trees or large thicket-forming shrubs; of 
southerly distribution east of the range-crest; frequent in fine soil, and 
ranging into less xerophytic habitats.............. Quercus association 
Dominant plants shrubs 
Shrubs tall and loosely branched, occurring mostly at and near the 
mountain-front, in coarse or rocky soils...... Cercocarpus association 
Shrubs low, Pep and densely branched, occurring mostly in the 
foo 
Plants i sere of northerly distribution, more frequent in the 
hihiet fOCthIS ee eS Arctostaphylos association 
Plants deciduous, of more a pesca more frequent in 
the tower Soetn. o6s e  k nothus association 
Dominant plants herbaceous; veuetation grassland, eae mostly of 
xerophytes 
Dominant plants including plains short-grasses of surface-rooted habit; 
lant population large and diverse, Foothills mixed grassland association 
Dominant plants mostly tufted bunch-grasses of deeper-rooted habit 
Bunch-grass association 
Typically developed in mesophytic or semi-mesophytic habitats (which are 
much less prays in the foothills than xerophytic habitats, being repre- 
sented chiefly on slopes and in ravines and canyons) 
Dominant ete evetureen trees... 55 2s sss Pseudotsuga association 
Dominant plants deciduous trees 
Typically bier along stream margins in open canyons 
Populus-Salix stream-side association 
Typically developed in less exposed situations cate preceding, as 
bottoms of v-shaped ravines and moist shaded slo 
Canyon en association 
— developed in moist ravines or slopes with humus soil; or, 10 
the higher foothills, in moist patches of the granite-gravel upland 
pen association 
