668 
their distal ends are submerged and since the littoral current and waves 
are sufficiently strong, no vegetation has gained a foothold. However, 
at the proximal extremities, triangular patches of newly formed beaches 
above high tide exist, and thereon the best expression of the Pes-capra 
formation can be observed. 
The tropical cosmopolitan creeper, Ipomoea pes-capre, is almost always 
present. This remarkable plant becomes established at a point lying 
a few meters landward from the upper limits of high tide, and it may, 
from a woody base, send out runners in all directions to a distance of 
as much as 10 meters; these latter take root and thus may become new 
centers ; often their ends reach to the sea, whereupon the portion which 
is bathed by the salt water is killed back. This plant takes possession 
by runners and seedlings as rapidly as the beach is formed. 
Other creepers found in this formation and having similar habitats 
are Spinifex squarrosus (the porcupine grass) and the legufne, Canava- 
lia obtusifolia. These plants, in addition to a few weeds, are practically 
the only ones to be observed on the strand at Lamao, although in similar 
physiographic situations in other parts of the Islands a greater diversity 
may be encountered. 
The deposit away from the mouth of the river usually is formed 
with less rapidity, and, correspondingly, the Pes-capre zone then is 
narrow or entirely absent, although in the older beaches in open places 
its elements may anywhere be found, excepting at the foot of the cliffs 
where it is usually wanting. Owing to the small size of the rivers of 
the Reserve, a rapid formation of the beach does not take place. In 
many parts of the Islands, where large streams flowing toward an open 
coast enter the sea, the triangular patches of the Pes-caprw formation 
bécome much larger, other plants, together with those mentioned, are 
then present and low dunes none of which, in these Islands, according 
to my observation, are over 2 meters in height are formed, on which the 
plants which have just been discussed act as sand binders. 
(b) The Barringtonia-Pandanus formation—On older portions of 
the beach, lying back of the Pes-caprew formation, or where this is 
absent fronting on the border of the sea, is the woody vegetation of 
the beach. This has been named by Schimper* the Barringtonia 
formation, from Barringtonia speciosa. On the Lamao strand this 
species is not present, although in similar situations it is common in 
other portions of the Islands.** 
The most striking plant of the beach of the Lamao Reserve and in 
many other parts of the Philippines is Pandanus tectorius, and for this 
reason the formation has been given the above name. Together with 
% Loc. ct., 391. 
“Much of the original vegetation of the beach at Lamao has been removed. 
This species may have been present. 
