592 



BOTANY 



PART II 



Order 3. Coniferae 



The Coniferae include conspicuous trees or shrubs with woody 

 stems. The possession of small, undivided, firm leaves, flat or 

 needle-shaped, of xerophilous structure, and usually lasting for several 

 seasons, is a common character of the plants of the order ; they thus 

 with a few exceptions, such as the Larch, belong to the evergreen 

 vegetation. All Conifers are profusely branched, and a distinction 

 into long and short shoots is evident in the genera Pinus, Larix, and 



d It 



FIG. 584. Girikgo biloba. Male branch with flower; the leaves are not yet full-grown, a, b, 

 Stamens ; c, female flower ; c?., fruit ; e, stone of same ; /, stone in cross section ; g, in longi- 

 tudinal section showing the embryo ; h, female flower with an exceptionally large number 

 of ovules borne on separate stalks. (Male flower and c, nat. size ; d, slightly reduced ; the 

 other figures magnified. After RICHARD ; a-d after EICHLEK.) 



Cedrus. In all cases the direction and rapidity of growth of the main 

 axis differs from that of the lateral branches. This is especially seen 

 in young individuals ; old trees are often more irregular in outline. 



The absence of vessels from the xylem of young plants and from 

 the secondary wood is an anatomical characteristic (cf . p. 151). Their 

 place is taken by large tracheides with peculiar bordered pits on the 

 radial walls ; these form a very uniform wood. The majority of the 

 Coniferae have resin abundantly present in all the parts of the plant. 



The Coniferae in contrast to the Cycadinae are mostly inhabitants 

 of temperate regions, and are among the trees which approach nearest 

 to the polar regions. Within the tropics they are mostly confined to 

 mountains. 



