298 SEIFRIZ: PLANTS ON MT. GEDEH, JAVA 
thrive, but rather their moisture requirements. The tree fern, 
for good development, requires abundant light as well as ample 
moisture and a cool temperature. Specimens found in the dark 
interior of the mountain rain-forests are invariably poor, and 
never have I seen a good stand of tree ferns but that the crowns 
were above all the surrounding vegetation, exposed to direct 
sunlight. 
In the gulch at Kandang Badak, where the above mentioned 
climatic conditions prevail, there is an excellent growth of tree 
ferns. Alsophila glauca var. densa and Cyathea orientalis are 
the two characteristic tall species. The genus Dicksonia, 
which does not exceed:a height of 10 feet as compared with a 
maximum of 50 feet for the other two genera, is represented by a 
single species, D. Blumei. When well developed the crown of 
the tree fern represents the most beautiful and delicate of all 
tropical foliage (Fic. 6). 
Gleichenia, like the tree fern, requires ample light for its best 
development, but is an exception among ferns in that it thrives 
wellin very dry soil. This fern is usually found in exposed sunny 
localities. Thus, it is very abundant in the open formation of 
the third subzone, where two species are common, a small, wiry 
one, G. linearis, and a large, coarse species, G. volubilis, which 
often sends out prostrate leafless shoots as much as 20 feet in 
length. Both form impenetrable thickets. 
Mosses are much less abundant here in the third subzone 
than they were in the second. Their absence is due probably 
to the open, sunny, and therefore less moist nature of this 
region. Lichens, on the other hand, are more numerous. The 
cosmopolitan Usnea occurs in great abundance. This lichen is 
typically, the world over, a genus of high altitudes or latitudes. 
The evidence that Mt. Gedeh is not a dead volcano is to be 
had along the trail in the third subzone, where two springs of 
steaming hot water gush forth and give rise to the brook 
“Tjipanas.”"* In the extremely hot water (about 130° F. )t 
of these springs there grows in great luxuriance a species of the 
*“Tii” is a Malay prefix ee “river” “Panas” the newcomer 
soon adds to his vocabulary; it means ‘ 
fT One often reads of higher "cemperatre a tee in which plants 
wing, but th rce is not over 
65° C. (150° F.). 
