KEY. BASED UPON LEAVES. 11 



ft 2 . Compound leaves. 

 c. Palmate with usually 



7 obovate leaflets 6. ^EscuLUS HIPPOCASTANUM. 



5 oblong-lanceolate leaflets 127. ^ESCULUS CALIFORNICA. 



c*. Pinnate with an odd terminal leaflet, rachis 



d. Furnished with prickles 106. XANTHOXYLUM CLAVA-HERCULIS. 



dj 2 . Not furnished with prickles ; leaflets all 

 e. Petiolulate, leaflets 

 /. 21-41, each with one or two pairs of glandular teeth at its base. 



4. AlLANTHUS GLANDULOSUS. 



/ 2 . 11-15, 



With prickle-like stipules, entire 80. EOBINIA PSEUDACACIA. 



With foliaceous deciduous stipules 84. PYRUS SAMBUCIFOLIA. 



/ 3 . 5-9, glabrous, coarsely serrate 157. SAMBUCUS GLAUCA. 



/ 4 . 7-9, ovate or lance-oblong, entire or obscurely serrate ; 



Petioles and branchlets glabrous 10. FRAXINUS AMERICANA. 



Petioles and branchlets velvety pubescent. 



31. FRAXINUS PUBESCENS. 

 / 5 . 3-5, lateral leaflets 



Petiolulate, irregularly toothed 54. ACER NEGUNDO. 



Sessile, subentire 77. PTELEA TRIFOLIATA. 



e 2 . Sessile or subsessile 

 /. Numerous (15-17) and pubescent, especially along the petiole and 



rachis. 



</. Leaflets ovate-lanceolate, finely serrate; pubescence of short, rust- 

 colored clammy hairs. 



Fruit subovoid, viscid-pubescent 14. JUGLANS CINEREA. 



Fruit globose, roughly dotted (not viscid-pubescent). 



35. JUGLANS NIGRA. 

 gr 2 . Leaflets lance-oblong, coarsely serrate; pubescence of copious, 



longer and white hairs ". 5. RHUS TYPHINA. 



/ 2 . 11-13. 115. CARYA AQUATICA. 



f\ 5-11. 



g. 5, quite glabrous; fruit a ridged nut about 1 in. long 1 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 3 . 7-9, epicarp thick and woody, leaflets 



Puberulent ; bark shaggy. . t 64. CARYA SULCATA. 



Tomentose and odorous 90. CARYA TOMENTOSA. 



g*. 7-n, 



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. 



# 3 . Decompound Leaves. 



c. Petioles smooth or pubescent; pinnnee 

 d. Remaining on during the season; leaves 

 e. Regularly bipinnate; pinnae 

 f. 2, leaflets, 



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



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



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



e 2 . Regularly bipinnate excepting for the lowest pair of single leaflets 



leaflets stalked 27. GYMNOCLADUS CANADENSIS. 



e 3 . Irregularly bipinnate, leaflets small and sessile, 



12-1 8 in number 109. GLEDITSCHIA MONOSPERMA. 



18-24 in number 27. GLEDITSCHIA TRIACANTHOS. 



<? 2 . Quickly falling away and petioles developing into phyllodia 



155. ACACIA MELANOXYLON. 

 c 2 . Petioles prickly, leaves large, with ovate, sessile serrate leaflets. 



8. ARALIA SPINOSA. 



