234 SYSTEMATIC BOTANY. 



sentatives are Leguminosse, Rubiaceae, and Cyper- 

 acese. The Elods guineends. Tallow-tree, Cotton, Sugar- 

 Cane, Ginger, Yams, Bananas, Cocoa-nuts, Papaws, 

 Oranges, and Pine-Apples also grow in this region. 



10. Central America, including Mexico and the northern 

 part of South America : Cacti and Piperaceae predomi- 

 nate. There are many Ferns and Orchids ; also Comppdtm, 

 Victoria regia, Palms, Pine-Apple, Vanilla, Chocolate, 

 Tobacco, Aloe, Logwood, Mahogany, Strychnos toxicaria, 

 etc. 



11. Basin of Amazon and Upper Parana: This is the 

 region of Palms and Melastomaceae. There are also 

 Tree-Ferns, Reeds, Grasses, parasitic Orchidaeece, Tilland- 

 sioB, Pasdfloras, Siphonia elastiea, and many other plants. 



12. Extra-Tropical America southward : Here are found 

 many arborescent Compositae ; also Protea, Polygala, 

 Oxalis, Aracauria, etc., with numerous species. 



13. Australia : The characteristic groups of this region 

 are the Eucalypti and the Epacridaceae (Ericacese). 

 There are also many Proteaceos and Banksias. 



FOSSIL BOTANY. 

 ig8. In the strata of rocks which form the crust of the 

 earth remains of plants, or the imprint of their leaves, 

 stems, etc., are found. These are called Fossil Plants. 

 In the uppermost layers, or those most recently formed, the 

 plants are found to be very nearly like those now living 

 on the earth. Often the very same species that now lives, 

 and in other cases very nearly related species, are met 

 with. , But the further we descend, or, in other words, the 

 older the rocks which we examine, the more unlike do 

 the plants gradually become. When we reach the strata 



