A HANDBOOK OF CONIFERS 



INTRODUCTION 



THE CONIFER.^. 



The trees and shrubs inchided under the Coniferse form a 

 group which was much better represented at earlier periods of 

 the world's history than at present, although it is still the 

 most important class of Gymnosperms. 



They comprise two families, forty-four genera, and about 380 

 species. With them is usually included the family Ginkgoacecp, 

 although recent research places it between the Conifera3 and 

 Cycadacece, with affinities to ferns. 



The geographical distribution of existing species of conifers is 

 of great interest, some being widely spread, while the majority 

 are confined for the most part to distinct areas, a few being 

 decidedly local. All are temperate or sub-tropical plants, 

 those found in tropical latitudes being confined to sub-tropical 

 or temperate elevations. 



Morphology. 



A detailed account of the anatomy and life-history of the 

 Coniferse is beyond the scope of the present work. There is a 

 large literature on this branch of the subject scattered through 

 various botanical publications. A good account of the group 

 is given by Coulter and Chamberlain, ^ and we do not propose 

 to give more than a general outline here or such information as 

 is necessary for purposes of identification. 



The Seedling Plant. 



Seedling conifers present special points of interest. In the 

 first place, the number, form, and size of the cotyledons or seed- 

 leaves vary greatly in different genera and species, and often 

 furnish sufficiently distinctive characters for identification. 

 The cotyledons usually appear above ground, but in the genus 

 Araucaria two forms of germination occur ; one in which the two 

 seed-leaves do not appear above the surface of the soil, as in 



^ Morphology of Gymnosperms (in 17). See also Masters, " Anatomy and Life 

 History of the Coniferse, " Journ. Linn. Soc. XXVII, 226 (1890). 



1 B 



