248 TROPICAL NATURE 



Besides these various kinds of trees and climbers, Avhich 

 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 



