1907] HERRE—LICHEN DISTRIBUTION 7B 
feet. On the Pacific side it is either very narrow or non-existent, 
but on the eastern side of the peninsula it extends as far south as 
Monterey Bay. A park-like oak forest is characteristic of the lower 
part of the region, and on these trees is a lichen flora remarkable for 
its variety and luxuriance. While but few lichens are confined to 
this area, many reach here their greatest development. Probably 
every tourist is struck with the appearance of the “‘lace lichen,” 
Ramalina reticulata (Noehd.) Krempelh., which decks the trees much 
s “Spanish moss” clothes the live oaks of the Gulf Coast. Other 
noticeable lichens are: 
Collema nigrescens (Huds.) Wainio; C. vespertilio (Ltf.) Wainio; Evernia 
prunastri (L.) Ach.; Lecanora subfusca (L.) Ach.; L. varia (Ehrh.) Nyl.; 
romelum stellans Tuck.; L. palmatum (Huds.) Mont.; nat lepidiota 
cyanolepra Tuck.; P. lepidiota coralliphora Tuck.; Prraatin soredica Nyl.; 
Placodium cerinum (Hedw.) Naeg. & Hepp.; P. ferrighsetam (Huds.) Hepp.; 
Physcia pulverulenta isidiigera A. Zahlbr.; Ramalina Menziesii Tuck.; Thelo- 
schistes lychneus laciniosa (Schaer.). 
The chaparral belt is not sharply delimited by contour lines or 
elevations, but depends upon climatic as well as physiographic 
features, the characteristic angiosperms of the chaparral being well- 
marked xerophytes. Hence we may have chaparral occurring on 
dry, barren hill-tops as low as four hundred feet, while we find more 
or less of it all the way to the summit of the Santa Cruz mountains. 
Very few lichens are exclusively chaparral, but where the conditions 
were favorable to such movement many conspicuous species have 
migrated from the adjacent forests. Certain components of the 
chaparral, such as the manzanitas, are almost wholly devoid of 
lichens ordinarily, because of their thick evergreen foliage and 
exfoliating bark. Others, as Ceanothus, Cercocarpus, and the scrub 
oaks, are conspicuous for their dense growth of lichens. The chief 
lichens in this formation are: 
Cetraria californica Tuck.; Cladonia verticillata Hoffm.; Lecanora palles- 
cens (L.) Schaer.; Parmelia enteromorpha .; Ramalina farinacea (L.) 
Ach.; Usnea plicata (Ach.) Nyl.; U. dasypoga (Ach.) Nyl.; U. florida (L.) 
Ach. 
The typical mountain forest of the Santa Cruz peninsula is the 
redwood and Douglas spruce formation, though much of the forested 
