248 
TROPICAL NATURE 
li 
Besides these various kinds of trees and climbers, which 
form the great mass of the equatorial forests and determine 
their general aspect, there are a number of forms of plants 
which are always more or less present, though in some parts 
scarce and in others in great profusion, and which largely aid 
in giving a special character to tropical as distinguished from 
temperate vegetation. Such are the various groups of palms, 
ferns, ginger-worts, and wild plantains, arums, orchids, and 
bamboos ; and under these heads we shall give a short account 
of the part they take in giving a distinctive aspect to the 
equatorial forests. 
Palms 
Although these are found throughout the tropics, and a 
few species even extend into the warmer parts of the tem- 
perate regions, they are yet so much more abundant and 
varied within the limits of the region we are discussing that 
they may be considered as among the most characteristic 
forms of vegetation of the equatorial zone. They are, how- 
ever, by no means generally present, and we may pass 
through miles of forest without even seeing a palm. In other 
parts they abound ; either forming a lower growth in the 
lofty forest, or in swamps and on hillsides sometimes rising 
up above the other trees. On river-banks they are especially 
conspicuous and elegant, bending gracefully over the stream, 
their fine foliage waving in the breeze, and their stems often 
draped with hanging creepers. 
The chief feature of the palm tribe consists in the 
cylindrical trunk crowned by a mass of large and somewhat 
rigid leaves. They vary in height from a few feet to that of 
the loftiest forest trees. Some are stemless, consisting only 
of a spreading crown of large pinnate leaves ; but the great 
majority have a trunk slender in proportion to its height. 
Some of the smaller species have stems no thicker than 
a lead pencil, and four or five feet high ; while the great 
Mauritia of the Amazon has a trunk full two feet in dia- 
meter, and more than one hundred feet high. Some 
species probably reach a height of two hundred feet, for 
Humboldt states that in South America he measured a 
palm, which was one hundred and ninety-two English feet 
