1348 



1817. Pinus paliistiis. 

 Leaf with two fibro-vascular bundles (a) ; several in- 

 ternal resin-duets (6) ; one layer of strengthening cells 

 ((■) beneath the epidermis and on the inner siiU of the 

 flbro-vaseular bundles; stomata (d) all around. 



Key for Detkrmininq Pines Without Cones (compan 

 Figs. 1815-1818). 

 A. Number of lv«. 5, only occa- 



vasciilar bundle 1. 



. Edges of Ivs. serrulate. 

 D. Lexqlh oflrs. IVi-S in. 

 E. limnchlets ijlabrous or 

 m-nrl;, .so. 

 F. The Irs. 6-li in. long: 



branchlets glaucous. 1. excelsa 

 FF. The Ivs. S-5 in. loiig: 

 branchlets not 

 glaucous, 

 a. Tree a rather dense 



2.: 



'. open pyra- 



Strobus 

 Cembra 



somewhat pen 

 lous, 4-6 in. Ion 

 TT. Needles stiff, 1%- 

 long. 



o 



.a 



1818 Pinus I 



Leaf with two fibro-vascular bundles (a) and several 

 parenchymatous resin -ducts (6); only one layer of 

 strengthening cells (c) beneath the epidermis: stomata 

 (d) all around. 



G. Back of Ivs. tvith 



fine white lines... .'>. Lambertiana 

 GO. Back of Ivs. usu- 

 ally not Until. 



H. Colornf Ir.s. I,hl- 

 ish o r d a r k 

 green 4. monticola 



hriijli' </!■< I II. . . . '.I. Koraiensis 



DD. Lemilli III' Irs. ■',-/'.. ill.: 



Ivs. USUI, III! Iirixtril, 



form in,, brush- likr 



tufts at the end of th, 



branchlets n. parviilora 



CO. Edges of Ivs. entire. 



D. tvs. lM-.-i in. long 7. flexilis 



DD. Lvs. l~r_. ill. liniii 15. Balfouriana 



vascular Ihiii.II.k' .■ : Ir.t. 



S-12 in. Iiimi. riqiii 10. Torreyana 



.X.Ni,ml..r,.flrii..:...r-l,.rl.iinlil 



in -''s 14. monophylla 



BB. r~'i'i''" 1. .,.',/,(, s .; or .7., 12. Parryana 



BBE. ' ."iiilllll 2. 



r. I ., I.iindir 1: 



I,. Mar.jn, .:l !•-„., iilii;.: Irs. 



U-i'- III. /'■ii[i i:i. edulis 



DD. Margin ■>!' Irs. S' mil. ill : 



lrs'.2-4iii. hill, I 11. Bungeana 



cc. Fibro-rasi ular luimUis i.': 



sheaths persistent. 



D. Branchlets glaucous: lvs. 



bluish or grayish green. 



(See al.soNo. 21.) 



E. ITaliil of Ir.s. .slender, 



ilrniiiiiiii, 17. Sabiniana 



EE. lliiliil of Irs. slr,iii,hl, 



F.'llin'ls rrni rrsiniiiis: 

 Irs. i:-l.' in. Inn,,. 

 ,1,1 rl: hi nisi, ,in , ».. .18. Ooulteri 

 FF. Jin, Is ml nr I ill Ir 



long, pair hinisli 



green 19. Jeffrey! 



DD. Branchlets not i,l,inr,uis: 

 lvs. dark yellow or 

 bright green. 

 E. Habit of lvs. slender, 



F. Ifrsin ■'(iucts inter- 



n,il L':!. palustris 



FF. It'i sill - iln,-ls pariii- 



hrnirii LM. Canariensis 



FFF. 7.'.,s-,» -dlirls prri,,h- 

 rral: hnds bright 



rhrslnut-hrown ll.'i. longifo-lia 



EE. naliil oflrs. stiff. 



F. Length of lvs. 6-12 in. 



