366 A HANDBOOK OF CONIFER.E 



Leaves with entire or obscurely toothed margins. 



Leaves 2-3 in. long, stout, rigid, curved. — P. fiexilis. 

 Leaves as in P. Cembra, but shorter l|-2 in. long. — P. pumila. 

 Leaves as in P. fiexilis, but the species is scarcely distinguish- 

 able in the absence of cones. — P. albicaulis. 



II. Leaves in Threes. 



Leaf- sheaths persistent. 



Leaves 6 in. or more long. 



Buds more or less resinous, 1-1| in, long, with points of 

 scales appressed. 

 Buds ovoid, stout, 1-I| in. long, sharply pointed. 

 Leaves very stout, yellowish green spreading, — 

 P, Coulteri. 

 Buds cylindric-conic, 1 in. long. Leaves dark green, 

 densely crowded on the branchlets. — P. ponderosa. 

 Buds narrowly cylindrical, 1 in. long. Leaves greyish 

 green, sparsely arranged. — P, Sabiniana. 

 Buds non-resinous, |-2 in. long, with points of scales free. 

 Young shoots stout, glaucous. Buds stout, cylindric- 

 conic or ovoid, 1 in. long, with brown scales, — P, 

 ponderosa, var. Jeffreyi. 

 Young shoots stout, orange brown. Buds with sUvery 



white fringed scales, l|-2 in. long. — P. palustris. 

 Young shoots slender, glaucous. Leaves very slender, 



drooping. Cones 3-4 in, long, — P. patula. 

 Young shoots yellow. Leaves slender. Cones 6-9 in. 



long, cylindjic-conic. — P, canariensis. 

 Leaves and shoots as in P. canariensis. Cones ovoid- 

 conic, 4-8 in. long. — P, longifolia. 

 Buds non-resinous, about | in, long, with the points of the 

 scales free and reflexed. 

 Young shoots yellowish brown. Leaves rigid in tufts at 

 end of branches. Scale leaves persistent, — P. Tceda. 

 Buds resinous, f in. long, points of scales free, young shoots 

 glaucous. Leaves 4-8 in., rigid, spreading, — P. Teocoie. 

 Leaves less than 6 in, long. 



Young shoots greenish. Buds cyUndrical, ^-| in, long. 

 Leaves bright or grass green, soft in texture, — P. 

 radiata. 

 Young shoots reddish brown. Buds cylindrical, f-1 in, 



long. Leaves rigid, dark green, — P, tuherculata. 

 Young shoots greenish. Buds cylindric-conic, |-| in. 

 long. Leaves rigid, often produced on the main 

 stem.— P, rigida.^ 



^ P. serotina is distingmshed from P. rigida by the longer leaves and different 

 cones. 



