CHAPARRAL. 29 
to three causes. On north slopes, and in fact in all protected situ- 
ations, fire is about the only agency which tends to limit the density 
of chaparral. Even when fires occur on such situations little per- 
manent damage is done, since the chaparral soon regains possession 
of the ground. On south slopes, on the other hand, exposure to 
intense heat and poor soil conditions results in a poor and scattered 
growth, while after fire the hard-baked ground is inhospitable to 
a new stand. 
VALUE OF THE DIFFERENT SPECIES. 
In the chaparral as it now exists the most desirable species are not 
the most numerous. Artificial means are needed to encourage the 
extension of the better sorts, to discourage the undesirables, and, 
possibly, to introduce foreign in place of some of the native species. 
The study of chaparral as a type of plant formation, and of the 
relative importance of the various genera as cover, is by no 
means complete. Much is yet to be done in determining which 
species are least ‘nflammable, are evergreen, cast the most shade, 
recover most quickly after burning, make the best soil binders, and 
have naturally a wide distribution and range. The following de- 
scription of those species which are important, either generally or in 
certain localities, or because their characteristics are particularly 
desirable, is given merely as a start in the right direction: 
Adenostoma fasciculatum, grease-wood, is the most abundant and 
widely distributed chaparral species in California, and is commonly 
known as chamisal. It ranges from sea level to 8,000 feet, is ever- 
green, tolerant, grows under all conditions of soil and exposure, and 
after burning makes a quick coppice growth from the surviving roots. 
In spite of these excellent qualities, it can hardly be considered a 
good cover for watersheds. It branches close to the ground, and 
has a shrublike form with many stems which sometimes attain a 
height of 10 feet. These stems are practically without permanent 
branches. This form does not produce much shade, nor does it pro- 
tect the ground from dry or hot winds. It 1s exceedingly inflam- 
mable, and not only makes a fast-running fire when in pure stand 
but also, when in mixture with other species, greatly increases the 
inflammability of the cover as a whole. It sends down a large tap 
root with few laterals, which makes it poor as a soil binder. This 
species should not be confounded with the “ grease-wood,” Sarcodatus, 
of the Rocky Mountain region. (Fig. 2.) 
Adenostoma sparsifolium, Yerba del Pasmo (spasm herb), is found 
in the southern portion of the chaparral region and is important in 
the northern portion of the Cleveland National Forest. Leiberg esti- 
mates that on certain eastern slopes, between 3,500 and 5,000 feet, it 
forms 55 per cent of the cover. It is exceedingly inflammable, and 
therefore undesirable. The Mexicans and Indians considered it a 
remedy for lockjaw, colds, cramps, inflammations, and snake bites. 
