398 
The Philippine Journal of Science 
1914 
Many colored rocks are strewn over the floor. The presence of 
a few dead stumps indicates a former vegetation, but at present 
the basin is plantless. 
Near the shore of Bombon Lake were a few strand plants 
and a little farther back an occasional clump of Saccharum 
spontaneum. By April, 1914, the strand flora and especially 
the flora of the area just back of the strand showed increased 
development. In addition to Saccharum, there were shrubs as 
follows: Acacia farnesiana (1), Tabernaemontana subglobosa 
(several), Ficus indica (several), Wendlandia luzoniensis (1), 
Morinda bracteata (very few), Semecarpus cuneiformis (1), 
and a hemiparasitic vine, Cassytha filiformis. 
In December, 1913, the whole slope east and southeast of the 
crater was plantless, presenting a gully-wom rugged surface 
from the rim of the crater to the lake. By April, 1914, how- 
ever, a number of plants were established on the strand and 
extended a short way up the sides of the gullies. On the strand 
was Ipomoea pes-caprae and back of it, in addition to the clumps 
of Saccharum, were Ficus indica (several), Acacia farnesiana 
(several), Tabernaemontana subglobosa (several), Pandanus 
tectorius (2), Eugenia jamb olana (2), Trema amboinensis (1), 
and a vine, Rourea erecta (1). Higher were a few clumps of 
Saccharum, well scattered to be sure, but exhibiting considerable 
advance over the four months previous. As yet shrubs were not 
present, and the upper slopes to the very rim of the crater were 
plantless. 
Northeastward from the crater runs a depression between 
two high ridges. In December, 1913, this valley as well as the 
ridge on each side was plantless. A narrow precipitous divide 
separates this valley from a basin 75 meters below. On this 
divide in December, 1913, were a few well scattered plants, 
including Saccharum spontaneum, Themeda gigantea, Ficus in- 
dica, and two clumps of Pandanus tectorius. By April, 1914, 
considerable plant development had taken place. On the ridges, 
particularly the western one, Mount Pinag-Ulbuan, there were 
a number of plants, some being present clear to the summit 
(250 meters). There were more grasses in point of number 
of individuals, but most of the vegetational appearance was 
given by the shrubs, Ficus indica, Monnda bracteata, Wend- 
landia luzoniensis, and Acacia farnesiana. 
The basin, formerly an eruptive center, is now the flat bed 
of a lake during the rainy season. With the exception of a very 
few bunches of Saccharum it was plantless. The walls have 
but little vegetation. It consists of bunches of Saccharum with 
