a7 2 BOTANICAL GAZETTE [APRIL 
area is given over to a growth of oaks, madrone, and other trees. In 
the redwood formation, sheltered by the dense canopy overhead, the 
lichens are but little affected by the frosts of winter, while the heavy 
summer fogs counteract the effect of the summer drouths. Having 
such favorable life-conditions for lichens, we may regard this region 
as the distributing center from which the chaparral has been stocked, 
while the foothill area has also largely been supplied in the same way. 
Arboreal forms such as the Stictaceae and certain Parmelias reach 
their highest vegetative and reproductive development in the dense 
redwood forests; while many others living on the earth or mosses are 
fertile and well grown only in the forests at 2000 feet or above, 
though they may descend in the foothills to as low as 150 feet. In 
this connection it may be well to call attention to the fact that the 
forests cover a much smaller area than formerly. For the last half- 
century the ax of the lumberman and forest fires have been actively 
engaged in the process of deforestation, and another generation may 
see many of the characteristic plants of the redwood forest extinct 
except within the limits of the Big Basin, which the state has pur- 
chased and set aside for a state park. Some of the more striking 
lichens of the forests are: 
Alectoria jubata (L.) Tuck.; Cetraria ciliaris (Ach.) Tuck.; C. lacunosa 
stenophylla Tuck.; Cladonia fideilents (Hoffm.) Nyl.; Leptogium albociliatum 
Desmaz.; L. eaiftucuicum platynum Tuck.; Nephromium helveticum Ach.; 
N. lusitanicum (Schaer.) Nyl.; N. anes nen rameum Nyl.; Parmelia entero- 
morpha Ach.; P. perforata (Wulf.) Ach.; P. tiliacea (Hoffm.) Ach.; Peltigera 
canina memnbreancea (Ach.) Nyl.; Pertuenria Wulfenii DC.; Lobaria pulmo- 
naria (L.) Hoffm.; L. scrobiculata (Scop.) DC.; Sticta aithrasgis Ach.; 5 
fuliginosa (Dicks.) S. Gray; S. limbata (Sm.) Ach.; Sphaerophorus globosus 
(Huds.); Usnea longissima Ach.; U. californica Herre 
By the mountain-peak area is meant the masses of exposed rock 
which may occur about the heads of heavily forested cafions, as well 
as the bare and rocky mountain peaks extending above the forests 
and chaparral. The lichens of this area are typically saxicolous, 
and while they may occur throughout the other formations wherever 
there is sufficient area of rock surface, some are found only along the 
highest mountains, swept by raw, bleak winds and exposed to a great 
diurnal as well as annual range of temperature. In summer this 
may rise to a sun temperature of 150° F. or more, and in winter may 
