278 EVOLUTION OF PLANTS 
ing plants are very numerous, and the tall trees are 
loaded down with giant creepers which are striving to 
reach the light overhead. The means by which this is 
accomplished are various. Some plants climb by twin- 
ing their slender stems about the support (Fig. 60, A), 
like the morning-glory or hop; others develop special 
climbing organs, ten- 
drils (B, C), which 
are either modified 
branches or parts of 
leaves. The climb- 
ing rattan palms, and 
some other tropical 
lianas, simply recline 
over the branches of 
trees, holding on by 
stout hooked prickles. 
A smaller number of 
Fic. 60 (Climbing plants). — A, twining Creepers, like the ivy 
stems of Mandevillea suaveolens; 1, leaf- and various tropical 
scar; B, leaf of sweet-pea with the ter- fe 
minal divisions transformed into tendrils, aroids, climb by 
ten; C, twining leaf-stalk of Solanum 
jasminoides. means of short root 
tendrils. 
PARASITES AND SAPROPHYTES 
Not to be confounded with the epiphytic plants are 
the true parasites, such as the mistletoe and dodder. 
Some, like the mistletoe and its numerous tropical re- 
lations, species of Loranthus, are only partially. para- 
sitic, being provided with more or less chlorophyll, so 
that they are capable of carbon assimilation. In the 
