DEVELOPMENT OF PLANTS 



343 



(c) The Principal Genera of Finales. The more important 

 genera of Pinales may be distinguished as follows : Finns or 

 pine, leaves long and needle-like, borne in fascicles on short stems 

 that are quite concealed by papery sheathing scales (Fig. 251, i). 

 Larir or larch, short needle-like leaves clustered in tufts on short 

 lateral branches. This is the only northern member of the order 

 with deciduous leaves. Picea or spruce, leaves angled or four- 

 sided, radiating from all sides of stem, petioles remaining on 

 branchlet after leaves fall, thus causing the rough appearance of 

 the branchlets (Fig. 260, 9). Tsuga or hemlock, leaves flat in 



7 



FIG. 260. Common examples of the Pinales : 5, Thuja or arbor vitae. 

 6, Strobilus of Chamaecyparis or southern white cedar. 7, strobilus of 

 Jioiipcnis or red cedar with fleshy scales fused into a berry-like fruit. 8, 

 branch of Taxus or yew. The seeds are produced singly in the axil of a 

 leaf on short lateral branches and nearly enveloped by a thick fleshy cup 

 that becomes bright red. 9, Picca or spruce. 



