12 KEY, BASED UPON LEAVES. 



g. 5, quite glabrous; fruit a ridged nut about 1 in. long with thick epicarp. 



36. CARYA ALBA. 

 gr 2 . 5-7 or 9, glabrous, epicarp thin; nut 



Small, thin-shelled 91. CARYA MICROCARPA. 



Larger, moderately thick-shelled 85. CARYA PORCINA. 



gr 8 . 7-9, epicarp thick and woody, leaflets 



Puberulent, bark shaggy 64. CARYA SULCATA. 



Tomentose and oderous 90. CARYA TOMENTOSA. 



fir 4 . 7-11, 



Lanceolate, acute at base, minutely glandular and pubescent 



beneath 37. C. AMARA. 



Oblong-lanceolate, glabrous, obtuse or rounded at base : fruit a 



samara, flat at base 62. FRAXINUS SAMBUCIFOLIA. 



6 3 . Decompound Leaves. 



C. Petioles smooth or pubescent; leaves 

 d. Regularly bi pinnate; pinnae 

 e. 2, leaflets, 



4-6, small (2-3 lines long) 128. CERCIDUM TORREYANUM. 



12-30 or more, 1-2 in.felong 129. PROSOPIS JULIFLORA. 



e. 2 7, leaflets, sessile 105. MELIA AZEDARACH. 



C? 2 . Regularly bipinnate excepting for the lowest pair of single leaflets ; 



leaflets stalked 27. GYMNOCLADUS CANADENSIS. 



d 3 . Irregularly bipinnate, leaflets small and sessile, 



12-18 in number 109. GLEDITSCHIA MONOSPERMA. 



18-24 in number 27. GLEDITSCHIA TRIACANTHOS. 



c 5 . Petioles prickly, leaves large, with ovate, sessile, serrate leaflets. 



8. ARALIA SPINOSA. 

 a". Subdeciduous Leaves a part only of the leaves falling in autumn, the rest 



remaining green through the winter. 



Obovate-spatulate, entire, shining green both sides . .118. QUERCUS AQUATICA. 

 3 . Persistent Leaves evergreen . 

 6. Needle-shaped and quite stiff, pointing every way. 

 C. In fascicles (Pinus) of 



d. Two each, a membraneous sheath inclosing the base of each fascicle, about 



e. 1 in. long, sheathes very short 99. P. BANKSIANA. 



e 2 . H-2 in. long and 



Stout; sheaths i in. or less; branchlets smooth and purple 



98. P. INOPS. 



Slender |- in. or more; branchlets rough-scaly 148. P. CONTORTA. 



e 3 . 2-3 in. long, slender with short sheaths 122. P. CLAUSA. 



e*. 3-5 in. long, slender; branchlets 



Rough. . 75. P. MITIS. 



Smooth 123. P. GLABRA. 



e 5 . 5-6 in. long, thicker, sheaths elongated 19. P. RESINOSA. 



d*. Three each and 



3-6 in. long 50. P. RIGIDA. 



5-8 in. long 121. P. SEROTINA. 



7-10 in. long, very stout 147. P. PONDEROSA. 



8-15 in. long 123. P. PALUSTRIS. 



d 3 . Both two and three each 125. P. CUBENSIS. 



d 4 . Five each, 3-5 in. long, sheath deciduous, 



Very slender: cones 4-6 in. long 49. P. STROBUS. 



Rather stout, cones 10-18 inches long 146. P. LAMBERTIANA. 



c 2 . Not in fascicles (scattered), ridged above and below and with elevated 

 persistent bases, 4 angled and 



