20 



PINE FAMILY 



KEY TO THE GENERA 



Foliage leaves all scattered, alternate 



a. Leaves flat linear, more or less twisted into 



two ranks 



(1) Buds small round resinous, cones up- 



right with decidous scales 



(2) Buds scaly not resinous, cones pendent 



with persistent scales 



(a) Leaves about 2 cm. long, their scars 



scarcely raised; bracts of cone long 



(b) Leaves about 1 cm. long, their scars 



raised on woody projections; bracts 

 of cone short 



b. Leaves four-sided in section, not at all two 



ranked, their scars raised on woody pro- 

 jections 

 Foliage leaves or some of them in fascicles 



a. Leaves deciduous, some scattered, others in 



large fascicles 



b. Leaves evergreen, in fascicles of 2-5 



Abies 



Pseudotsugc 



Tsuga 



Picea 



Larix 

 Pinus 



Cupressineae Cypress Tribe 



Leaves and cone-scales opposite or in whorls, leaves needle-like or 

 reduced to small flattened scales which adhere to the twigs, stamens often 

 with more than two pollen sacs, pistillate cones without distinct "bracts," 

 seeds erect, 1-40 upon each seed-bearing scale. 



KEY TO THE GENERA 



1. Cones woody, twigs and spray flat, leaves scale- 



like, of two alternating types Thuja 



2. Mature cones fleshy, twigs and spray not flat- 



tened 



a. Leaves usually opposite, scale-like on ma- 



ture twigs Sabina 



b. Leaves in whorls of three, all needle-like Juniperus 



Abies Jussieu 1789 Fir 



(L. and Gr. a b i e s, fir tree.) 



Evergreen trees, sometimes shrubby at high altitudes, trunk straight, 



running to the top of the tree, branches irregular or whorled, horizontal ; 



leaves needle-like but usually flat and blunt, sessile, scattered and borne 



