268 



GYMNOSPERBOE. 



ginal form (atavism). The so-called " Eetinospora " species are 

 seedling-forms of Biota, Thuja, Chamcecyparis, which have been 

 propagated by cuttings, and retain the seedling-form. The flowers 

 are monoecious or dioecious. The male flowers are short, and 

 have shield-like stamens, bearing most frequently several pollen- 

 sacs. The cover-scales and ovuliferous scales are entirely fused 

 together and form undivided cone-scales, opposite or u-horled; the 

 orttliftTuus scales have slight projections near the base on which 

 l-2-several erect ovules are developed (Fig. 274). Most frequently 

 2 cotyledons. Evergreen trees and shrubs. 



FIG. 270. 

 goveniana 



FIG. 271. Portion of a branch 

 of Thuja orientalisl (magnified). 

 The leaf at the base on the right 

 has a branch in its axil. 



FIG. 272. Seedling of 

 Thuja occidentalis. The 

 branch (g) is borne in 

 the axil of the leaf s. 



Juniperus (Juniper). Dioecious. The cone-scales become fleshy 

 and fuse together to form most frequently a 1-3 seeded 

 "berry-cone." J. communis (Common Juniper) has acicular leaves, borne in 

 whorls of three, and the " berry-cone " is formed by a trimerous whorl of coue- 

 scales (Fig. 273). J. sabina and J. virginiana have " berry-cones" formed from 

 several dimerous whorls of cone-scales; the leaves are connate and opposite, 

 needle- and scale-like leaves are found on the same plant. 



(Cypress). Monoecious. The cones are spherical ; the 

 cone-scales shield-like, generally five-cornered and woody (Fig. 

 2~n), each having many seeds. The leaves are scale-like. Thuja. 



