PINACEAE 



KEY TO THE JAPANESE GENERA 

 Subfam. ABIETEAE 



Fruit maturing in two seasons; leaves fascicled, needle-shaped, enclosed at the base in 



a membranous sheath PINUS. 



Fruit maturing in one season. 



Leaves scattered on leading shoots and in rosettes on short spur-like branchlets, de- 

 ciduous LARIX. 



Leaves scattered, linear, persistent. 



Cones pendulous, the scales persistent on the axis. 

 Branchlets roughened by the persistent leaf -bases; leaves falling off in drying; 



bracts shorter than the cone-scales. 

 Leaves sessile, 4-sided, or flattened and stomatiferous above .... PICEA. 



Leaves stalked, flattened and stomatiferous below TSUGA. 



Branchlets not roughened by leaf -bases; leaves stalked, flattened, not falling off 



in drying; bracts longer than the cone-scales PSEUDOTSUGA. 



Cones erect, their scales deciduous from the axis, longer or shorter than the bracts. 

 Leaves sessile, flat ABIES. 



Subfam. TAXODIEAE 



Fruit maturing in two seasons; leaves crowded, scale-like, with long, narrow, strap- 

 shaped cladodes arising from their axils and arranged in whorls of from 20 to 30 like 

 the ribs of an umbrella SCIADOPITYS. 



Fruit maturing in one season; leaves spirally arranged in 5 rows, short, linear-subulate, 

 irregularly 4-sided, falcately incurved, rarely straight and spreading, keeled on the 

 lower side, sessile CEYPTOMEBIA. 



Subfam. CUPRESSEAE 



Fruit a cone, maturing in one season; leaves usually scale-like, often dimorphic. 



Cones broadly ovoid or globose, the scales rhomboidal, imbricated; seeds five at the 



base of each scale THUJOPSIS. 



Cones oblong, the scales oblong, in four decussate pairs, the middle ones only fertile; 



seeds two at the base of each scale THUJA. 



Cones globose or nearly so, the scales peltate, from 8 to 12; seeds from 2 to 6 on 



each scale CHAMAECYPARIS. 



Fruit a berry, maturing in two or three seasons; flowers dioecious; leaves decussate or 

 in threes, subulate or scale-like, often of two forms JUNIPERUS. 



Subfam. ABIETEAE Spach 



PINUS L. 



The genus Pinus is widely distributed through the Northern Hemisphere from 

 the Arctic Circle southward to the Bahamas, the West Indies and the mountains 

 of Central America in the New World; to the Canary Islands, northern Africa, 

 Sumatra and to the Philippine Islands in the Old World. The genus has its greatest 

 development in western North America, where 28 species are found. The latest 

 monographer, Shaw (Genus Pinus, 24 [1914]), recognizes 66 species, of which 43 



