ALABAMA FLORA AND EUROPEAN FLORA. 



43 



EUROPE AND THE MEDITERRANEAN REGION. 



The r(4ationship between the flora of Ahibama and that of Europe 

 and the parts of Asia and Africa bordering upon the Mediterranean 

 Sea is indicated by their having in common about 100 families with 

 about 230 genera, this being nearlj' 35 per cent of the genera indig- 

 enous to Alabama, with 55 species which occur in Alabama and also 

 in western Europe and in the Mediterranean region, chiefly the former. 

 Of the ar])oreal plant formation nearly all of our deciduous catkin- 

 bearing trees and most of the shrubs are represented by closeh' allied 

 species in those regions. Some of these genera are represented far to 

 the north in the European-Asiatic forest belt, such as willow, cotton- 

 wood (Populus), birch and alder, and pine, while walnut, beech, oak, 

 hornbeam, hazelnut, ash, maple, plum and cherry, pear and apple, and 

 the savin are widel}^ diffused over the more temperate regions of 

 Europe. In the Mediterranean region our white cedar (Chamaec}^- 

 paris) finds itself represented in the cypress (Cupressus), from which 

 it differs b}' a mere technical character, and Celtis (hackberry), Cercis, 

 and Storax are represented in the same region. It is a remarkable fact 

 that in no one of these genera is the European species identical with that 

 found in Alabama. The ferns and allied families are represented by 

 4: families with 12 genera; of these 7 belong to the ferns proper with 

 5 identical species, 2 to the Ophioglossaceae, 1 to the Lj^copodiaceae, 

 1 to the Selaginellaceae, and 1 to the Equisetaceae. 



The followino- table exhibits the relation of these two floras: 



Genera and species common to Alabama and Europe, with Mediterranean Asia and Africa. 



1 Including Polypodiaceae, HjTnenophyllaceae, 



and Osmundaeeae. 

 '^ Including Potamogeton, .5 species. 



3 Here used in the Iiroader sen.se. 



<Tillaea. 



6 Drosera. 



