IN ANGIOSPERMAE. ROOT-CLIMBERS 



157 



A. CLIMBING PLANTS. 



1. ROOT-CLIMBERS. 



The configuration of the juvenile leaf and of the adult leaf is very 

 different in many climbing species of Aroideae. I myself examined this 



difference in an aroid, probably a species 

 of Monstera or Philodendron, which 

 climbed up the trees of Erythrina pro- 

 tecting a plantation of cacao in Vene- 

 zuela (Fig. 95). The earlier leaves are 

 sessile or very shortly stalked and lie 

 closely adpressed to the surface of the 



FIG. 96. 'Pothos celatocaulis.' Juvenile form. The dis- 

 tichously leaved shoot grows upon the stem of a tree-fern to 

 the surface of which the leaves of the aroid are adpressed. 



stem, and thus protect the young anchor- 

 ing roots of the plant. Subsequently 

 the form is changed ; the leaves acquire 

 a larger lamina and a longer stalk and 

 stand out from the stem, until finally 

 the large leaves with cut margin are 

 produced which are characteristic of the 

 mature plant. The aroid cultivated in gardens as ' Pothos celatocaulis ' is 

 undoubtedly a juvenile form of this kind, the mature stages of which are not 

 known, although the plant often reaches a length of many yards (Fig. 96). 



FIG. 0.5. Young plant of a climbing species of 

 Aroideae. The lower leaves are closely adpressed 

 to the stem of the tree upon which the plant grows 

 as is the case in 'Pothos celatocaulis,' the upper 

 leaves have another form. From a photograph 

 taken at San Esteban, Venezuela. 



