Botany of Mariposa. 235 
less rounded hills, which rise at times almost to mountains and are 
covered principally with thin grass. The intervening valleys and 
the more gentle slopes form the principal agricultural portion of the 
county, but the natural vegetation of the district is very limited in 
species and consists mostly of common Californian forms. The only 
trees are a few scattered post oaks ( Quercus Douglasii) or an occa- 
sional water oak (Q. /obata). This tract extends from the county 
line to beyond Hornitos on the east. 
Then the hills begin to grow steeper and higher, the valleys nar- 
rower, the cafions and ravines more precipitous, and we enter the 
second zone or the wooded foothills. Here the hills are or would 
be almost anywhere else mountains, some of them, like Mt. Bullion, 
rising to over 5,000 feet. For the most part they are densely cov- 
ered with “chaparral” or “brush,” as the Eastern people call it, 
though the north sides of the hills and the banks of the streams 
originally at least displayed a good growth of large timber. The 
scattered post oaks become larger and more abundant. The live 
oak ( Q. Wislizeni) becomes conspicuous on the dry hill-sides while 
the black oak (QO. Kelloggii) is frequent and attains a good size in 
favorable spots; but it is the chaparral which principally covers the 
mountain sides of this region, and which gives character to hundreds 
of square miles. Nothing can be more rough, more repulsive, more 
inhospitable than these mountains, mere huge, dry masses of chap- 
arral-covered rocks and clay slopes, through which the Merced and 
its branches force their way in the lower part of their course within 
our limits. This chapparal consists of a few kinds of gregarious, 
‘ niostly evergreen shrubs, such as the chemisal (Adenostoma) 
which alone covers many thousand acres. With this are associated 
the manzanitas (Arctostaphylos tomentosa, pungens and glauca) 
and the buckthorn ( Ceanothus cuneatus) the latter perhaps the most 
troublesome obstacle to the clearing of agricultural land that we 
have. Scrubby forms of the live, post and black oaks form in 
- many places a portion of the tangled mass. Frequently the buck- 
eye (.4sculus Californica) appears, the deerbrush ( Ceanothus di- 
varicatus ), the flowering ash (Fraxinus dipetala), the small mount- 
ain mahogany (Cercocarpus parvifolius) are not rare. Along the 
streams the Syringa (Philadelphus Lewisii) and the California 
strawberry tree ( Calycanthus occidentalis ) are especially noticeable. 
In this zone the coniferous trees first appear. The yellow pines 
