23° 



ZONES AND REGIONS 



Gymnospermae. 



[Pt. Ill, Sfxt. I 



Gymnosperms are of quite subordinate significance in the megathermic 

 flora. Conifcrac are almost entirely absent ; they are found between the 

 tropics wellnigh onl}- on high mountain chains, outside the tropical climate 

 Cycadeae (Fig. 117) are a highly characteristic feature of the tropical flora 

 but are subordinate as regards the number of species and individuals. Tht 

 species of Gnetum which completely agree with Dicotyledones in thai 



Fig. 117. Dioon edule. Mexico. CeiTO Colorada, south-east from Jabpa. From a photogiap 



by Stahl. 



vegetative organs are also a subordinate and at the same time inconspicuoi 

 element in the flora. 



Monocotyledone^. 



Monocotyledones supply the most characteristic features of the tropic 

 flora. In the first place, this is true of the Pahnac, which however ov 

 their predominance, in tropical landscapes chiefly at any rate, to cultivatio 

 The latter statement is especially true of the coconut palm. Cocos nucifei 



