I 
XII, c, 4 Brown, Merrill and Yates: Volcano Island 193 
Gates in describing this vegetation in 1914 says : 
Canavalia tends to extend inward away from the water to a very much 
greater extent than Ipomoea, which is usually confined to the shore. Excep- 
tions occurred on the lava ridges of Mount Binintiang Munti, where Ipomoea 
spread a considerable distance from the shore, and in a few places on the 
eastern side of the island, where unaccompanied with Canavalia, Ipomoea 
spread back several meters and attained an altitude of about 30 meters on 
the mud slope. 
FERNS 
At low altitudes there are many ravines from 2 to 3 meters 
in depth and less than 1 meter in width. On the northern slopes 
these ravines have developed into veritable canons, often with 
perpendicular walls many meters in height. In these there is 
frequently a considerable development of a fern flora and a few 
species of mosses and hepatics. The most prominent ferns are : 
Acrostichum aureum. 
Ceropteris calomelanos. 
Nephrolepis biserrata. 
Pteris vittata, 
Pteris quadriaurita. 
Onychium siliquosum. 
Odontosoria chinensis. 
Blechnum orientale. 
Cheilanthes tenuifolia. 
Adiantum philippense. 
AQUATIC VEGETATION 
We have made no special study of the aquatic vegetation 
around the island. Our knowledge of this was obtained from 
observations made while walking around the whole shore of the 
island, except an inaccessible portion at the base of Mount Binin- 
tiang Malaqui, and while bathing at a number of different points. 
On some of the rocks there is a considerable growth of Clado- 
phora, but this was the only attached vegetation observed with 
the exception of two small plants of Vallisneria gigantea, the 
roots of which were half exposed by the action of the waves. 
Along the northern shore were found a considerable quantity of 
broken Vallisneria and a single piece of Ceratophyllum demer- 
sum that had been cast up by the waves. Occasional plants 
of the floating aroid Pistia stratiotes were observed at different 
places along the shore. 
' ASSOCIATIONS 
The vegetation of Volcano Island is not readily divided into 
formations or associations. This is a natural result of similar 
external conditions over the whole area and the scarcity of 
vegetation, which consists, either entirely of Saccharum, or of 
Gates, F. C., Philip. Journ. Sci. 9 (1914) Bot. 319-434. 
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