406 
The Philippine Journal of Science 
1914 
The ground is wet on account of its close proximity to the water 
table level of Lake Bombon. Later on, more associations may 
become established, but at present only the following can be 
satisfactorily recognized and none of them are particularly well 
developed : 
THE CYNODON ASSOCIATION 
This association of grasses, which grows along the shore, 
sometimes down into the water, is fairly well represented in a 
few places at the foot of bluffs in the western part of the north 
shore. It is sparingly present in the bays in the northeast 
region and is indicated in a few other places along the shores 
of the northern parts of the east and the west coasts. 
With the dominant species, Cynodon dactylon, may occasion- 
ally be associated Dactyloctenium segyptium, Mariscus stuppeus, 
and Ricinus communis, while to a limited extent Panicum repens 
and Phragmites vulgaris may be present as invaders. 
THE PANICUM REPENS ASSOCIATION 
At the foot of the bluffs on the north coast, sometimes project- 
ing into the water, is a poor representation of this moist ground 
grass association. With it may occur Wedelia biflora and in 
one instance Vernonia cinerea and a few seedlings of Muntingia 
calabura were observed. This association is apparently not 
making much headway for it is subject to being washed away 
by the lake during storms, to being buried as a result of erosion 
of the bluffs, and to being shaded out of existance by Phragmites 
in flats or by shrubs at the foot of the bluff. 
• THE PHRAGMITES ASSOCIATION 
This association of tall marsh grass is represented by plants 
of Phragmites vulgaris, openly disposed. Nowhere has the 
typical dense growth been attained. Very few plants are to 
be found associated with it where the ground is wet to the 
surface. This is probably due to the thorough control of the 
ground by the very extensive root system possessed by Phrag- 
mites. On slightly higher ground invasion into the fairly open 
above-ground growth of Phragmites is not difficult, as the abund- 
ance and diversity of species testifies. These are Wedelia biflora, 
Ricinus communis (many), lpomoea triloba, Portulaca oleracea, 
Canavalia ensiformis, Sida acuta, Triumfetta bartramia, Maris- 
cus stuppeus, and Leucas javanica as well as seedlings of Trema 
amboinensis, Macaranga tanarius, Acacia farnesiana, and Mun- 
tingia calabura. Long above-ground runners from plants of 
