318 The Philippine Journal of Science 
under which it occurs on Mount Banahao which is a typical 
locality. 
Mount Banahao, on the Island of Luzon, is one of three extinct 
volcanic cones which form an isolated mountain mass on the 
boundary between the Provinces of Laguna and Tayabas. Mount 
Banahao is the largest of the three and has an elevation of 
about 2,300 meters. The next highest is Mount San Cristobal 
which lies to the east of Mount Banahao and is connected with 
the latter by a narrow saddle. The third one, Lukban Peak, 
is a small cone on the northeastern side of Mount Banahao. All 
three peaks are regular cones. Mount Banahao has a large 
crater which is open toward the south. The sides of the crater 
are very steep, while the rim is narrow and knifelike. 
The area in which the rate of growth of Podocarpus imbrica- 
tus was studied is near the crater rim on the north side of Mount 
Banahao near the place where the trail from Majayjay reaches 
the summit. The elevation at this point is about 2,100 meters. 
The forest is fairly open and consists of two stories of trees. 
The first or dominant story is composed almost entirely of 
Podocarpus imbricatus. Besides this species there are a few 
specimens of Podocarpus costalis Presl. The tallest individuals 
of Podocarpus imbricatus reach heights of about 14 meters while 
the average height of the main canopy is about 12 meters. A 
large part of the trees have a tendency to lean in a direction 
away from the slope of the mountain (Plate XVII, figs. 1 and 
2). The second story is composed of a few species of dicotyl- 
edonous trees the most prominent of which is Symplocos whit- 
fordii Brand. Among the other prominent species are Drimys 
piperita Hook, f., Homalanthus alpinus Elm., Clethra lancifoUa 
Turcz., Rhododendron kochii Stein, Symplocos luzonensis Rolfe, 
and Ilex serrata Thunb. The undergrowth is scanty and the 
ground is largely bare. The most important element in the 
undergrowth is a semiwoody herb, Strobilanthes pluriformis 
C. B. Clarke. In places a small creeping plant, Nertera depressa 
Banks, forms conspicuous patches. Mosses, filmy ferns, and a 
few liverworts are scattered here and there. Epiphytes are 
much less conspicuous than on most mountain tops in the Philip- 
pines. There are a few mosses on the trees, but they are not 
prominent. Phanerogamic epiphytes are even less conspicuous 
than mosses. The most abundant species is a small orchid, 
Dendrochilum venustulum Pfitz. ; this plant occurs in consider- 
able numbers in the tops of the trees, and its small yellow flowers 
are rather showy during the blooming season. Rhododendron 
