KEY, BASED UPON LEAVES. 11 



g. Moderately incised with broad lobes which are 



Sparingly sinuate-toothed 7. ACER SACCHARINUM. 



Irregularly serrate and notched. . . 53. ACER RUBRUM. 



Sharply and finely doubly serrate 79. ACER PENNSYLVANICUM. 



/ 9 . Alternate, tendril bearing vine 78. VITIS AESTIVALIS. 



g. Deeply incised with more or less acute sinuses and narrow divisions. 

 Star-shaped, lobes glandular serrate. 



60. LlQUIDAMBAR SLYRACIFLUA 



Palmate, lobes incisely toothed 26. ACER DASYCARPUM. 



c 2 . Linear, sessile in delicate 2-ranked sprays 119. TAXODIUM DISTICHUM. 



C 3 . Needle-shaped without distinction of blade and petiole short, about 1 in. 



in length, soft and in fascicles of many each 23. LARIX AMERICANA. 



9 . Compound leaves. 



c. Palmate, with 7, obovate, serrate leaflets 6. AESCULUS HIPPOCASTANUM. 



c' 2 . Pinnate and with an odd terminal leaflet, rachis 



d. Finished with prickles 106. XANTHOXYLUM CLAVA.HERCULIS. 



e? 2 . Not-finished with prickles ; leaflets all 

 e. Petiolulate, leaflets 

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



4. AlLANTHUS GLANDULOSDS. 

 /'. 11-15, 



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



With stipules, serrate .- 84. PYRUS SAMBUCIFOLIA. 



f 3 . 7-9, ovate or lance-oblong, entire or obscurely serrate; 



Petioles and branchlets glabrous 10. FRAXINUS AMERICANA. 



Petioles and branchlets velvety pubescent. 31. FRAXINTJS PUBESCENS. 

 / 4 . 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. 

 g. 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. 



/ 8 - (5-11). 



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. 



gf 3 . 7-9, epicarp thick and woody, leaflets 



Puberulent, bark shaggy ... .64. CARYA SULCATA. 



Tomentose and oderous 90. CARYA TOMENTOSA. 



