270 THE CULTIVATED EVERGREENS 



all mentioned below except P. gemmata, Rehd, & Wils., P. hirtella, Rehd. & 

 Wils., and P. Neoveitchii, Mast., from China, which are not in cultivation. 



A. Leaves quadrangular or slightly compressed, with stomatic lines 

 on all foiu- sides. 

 B. Leaf nearly equally stomatiferous on all foiu- sides, in cross- 

 section as high as broad or higher than broad. _ 

 c. Branchlets glabrous (sometimes pubescent in P. Abies 

 and in a var. of P. glauca). 

 D. Direction of leaves, at ■ least those of the upper ranks, 

 more or less pointing forward. 

 E. Color of branchlets gray or yellowish to orange. 

 F. Disposition of leaves radial, %-l^ inches long: 

 branchlets pendulous: cones 3-6 inches long. 

 G. Winter-buds pointed: leaves 1-1% inches long, 



slender, gradually pointed 1. P. Sniithiana 



GG. Winter-buds obtuse: leaves %-lM inches long, 



rather abruptly pointed 2. P. Schrenkiana 



FF. Disposition of leaves pectinate below: branchlets 

 not pendulous: winter-buds acute or acutish. 

 G. Branchlets pale gray or yellowish. 



H. Length of leaves 3^-% inch: pulvini produced 



into a short petiole 3. P. Watsoniana 



HH. Length of leaves 14-H inch: pulvini scarcely 



produced into a petiole i. P. Wilsoni 



GG. Branchlets bright yellow to orange: pulvini pro- 

 duced into a stafk ^ inch long 5. P. aurantiaca 



EE. Color of branchlets brown or yellowish-brown. 



F. Cone i-6 inches long: leaves bright or dark green, 



often spiny-pointed, usually yi'H, inch long. 



G. Winter-buds not resinous, the terminal one with 



a few acuminate, keeled and ciliate scales at 



base: cone-scales not or slightly emarglnate ... 10. P. Abies 



GG. Winter-buds resinous, their scales ah obtuse, 



glabrous, revolute at apex: lower cone-scales 



deeply emarginate 8. P. keterolepis 



FF. Cone lJ4-23^ inches long: leaves usually more or 

 less glaucous, acute or obtusish, usually M-% 

 inches long: bud-scales round and more or less 



revolute at apex, often emarginate 19. P. glauca 



DD. Direction of leaves spreading more or less radially at 

 nearly right angles. 

 E. Winter-buds not or slightly resinous: leaves 3^-1 inch 

 long. 

 F. Bud-scales more or less revolute at apex, light yel- 

 lowish-brown: leaves in cross-section about as 



high as broad, usually bluish-green 21. P. pvngens 



FF. Bud-scales firmly appressed, dark brown: leaves 



higher than broad, bright green 7. P. polita 



EE. Winter-buds very resinous: leaves }/i~% inch long. 6. P.Maximowiczii 

 cc. Branchlets pubescent. 



D. Terminal winter-buds without subulate scales. 



