
1 
k, 
ee Oe eee ee ae ae Sere eT ee 

PLANT GEOGRAPHY 439 
trees. ‘The trees of the top, or dominant, story form a nearly 
closed canopy which is frequently 60 meters or more in height. 
The crowns of the second story are beneath those of the domi- 
nant story and, like those of the dominant story, frequently 
form a nearly closed canopy. The trees of the third, or lowest, 
story are usually small and slender and have small open crowns. 

Fig. 489. Climbing palms (rattans) in Philippine rain forest 
The presence of these three stories of different trees is not usu- 
ally evident on casual observation, for the composition of all 
the stories is very complex and few of the trees present any 
striking peculiarities. Moreover, smaller trees of a higher story 
always occur in a lower story as well as between the differ- 
ent stories, while the different species of a story have different 
heights. Erect palms are frequently numerous in the lower 
stories but are seldom a prominent part of the vegetation. 
Beneath the tree stories there is a ground covering, the com- 
position of which varies in different situations. In rather dry 
areas, particularly on ridges, it may consist largely of woody 
