300 THE CULTIVATED EVERGREENS 



EE. Stomata on back of leaves: leaves 3-4 inches long: 



branchlets pubescent 7. P. Lambertiana 



cc. Margin of leaves entire (remotely serrulate in a var. of 

 No. 4). 

 D. Sheaths deciduous the first year: leaves lJ^-3 inches 

 long, with stomatic lines on back. 

 E. Young shoots glabrous or puberulous: leaves stout . . 3. P. albicaulis 

 EE. Young shoots puberulous: leaves slender, not more 



than 2*5 inch thick 4. P. flexilis 



DD. Sheaths deciduous during the second or third year: 



leaves 1-1% inches long, without stomata on back. 



E. Branchlets dark orange-brown, puberulous at first: 



leaves without resinous exudations 15. P. Balfouriana 



EE. Branchlets light orange, glabrous or nearly so: 



leaves sprinkled with resinous exudations 16. P. aristata 



BB. Leaves 1-4, only occasionally 5 : branchlets glabrous. 



c. Margin of leaves serrulate; leaves 3: bark of trunk exfolia- 

 ting in large thin plates 14. P. Bungcana 



cc. Margin of leaves entire: leaves 1-4: bark fissured 13. P. cembroides 



AA. Bracts subtending the leaf-clusters decurrent; sheaths of leaf- 

 clusters persistent. 

 B. Number of leaves 3-5, only occasionally 2. 



c. Leaves 5, 8-12 inches long (see also var. of No. 29) 49. P. Torreyana 



cc. Leaves 3. 



D. Leaf slender, drooping, 8-18 inches long. 

 E. Branchlets not bloomy. 



F. Winter-buds white, with conspicuously fringed 

 scales: leaves 8-18 inches long, with internal 



resin-ducts 34. P. palustris 



FF. Winter-buds brown: leaves 8-12 inches long, with 



marginal resin-ducts 17. P. longifolia 



EE. Branchlets bloomy. 



F. Winter-buds with conspicuously long-fimbriate re- 

 curved scales, not resinous : leaves with marginal 



resin-ducts: spring-shoots uninodal 18. P. canariensis 



FF. Winter-buds not conspicuously fringed, resinous: 

 leaves with medial resin-ducts: spring-shoots 



multinodal 48. P. Sabiniana 



DD. Leaf stiff and straight. 



E. Branchlets glaucous: leaves bluish- or grayish-green. 

 F. Winter-buds not or slightly resinous: leaves 4-8 

 inches long. 

 G. Bloom on branchlets slight: leaves often 2, dark 

 or bluish-green. 

 H. Bark of older branchlets peeling off in well- 

 defined plates : leaves 4-7 inches long, with 

 marginal or with marginal and medial 



resin-ducts 28. P. sinensis 



HH. Bark of older branchlets peeling off in ir- 

 regular scales: leaves 3-5 inches long, 

 with medial or with medial and internal 

 resin-ducts 31. P. echinafa 



