KEY, BASED UPON FRUIT. 



e 2 . Globular, purple or purplish-black, small aud 



Solitary, of a sweet-sugary flavor 12. CELTIS OCCIDENTALS. 



Racemed (or partially so), of a vinous slightly astringent flavor. 



29. PllUNUS SEROTINA. 

 C 3 . Drupe-like but containing more than one seed, subglobose. 



(1. Five-seeded and crowned with the persistent calyx-teeth and styles (Aralia), 



purple-black, numerous, in panicled umbels. ... 8. A. SPINOSA. 



d*. Two to five-seeded, bluish-black with white bloom, scaly bracted under- 

 neath (Juniperus) 25. J. VIRGINIANA, 



C 4 . Nut hard, single coat, and furnished with an involucral cup or covering. 

 d. Ovoid oblong or ellipsoidal, surrounded at its base with an involucral cup 



(Quercus) which is 

 e Shallow, saucer-shaped and composed of 



Smooth, closely-appressed scales, on wood of preceding year's growth. 



15. Q. RUBRA. 



Rough-tubercled, closely-appressed scales, on ne.w wood of the season, 



38. Q. ALBA. 



e. Deep and composed of distinctly imbricated scales, the upper ones usually 

 filiform and making a fringed margin; on new wood of the season, 



39. QUERCUS MACROCARPA. 



df 2 . Club-shaped, short, surrounded with stiff hairs, tipped with the persistent 

 recurved style and arranged in globular heads. 



13 , PLATANUS OCCIDENTALS. 

 d 3 . Achenium-like, small and borne in short catkins. 



Inclosed in a membranous inflated sac, catkin hop-like. 



41. OSTRYA VlRGINICA. 



Subtended by an enlarged leafy bract.. . . 42. CARPINUS CAROLINIANA. 



c 5 . Nut-like, but not invested with an involucre, globose, about as large as 



peas and arranged in cymes with a large, leaf-like bract attached to each 



peduncle (Tilia) 3. T. AMERICANA. 



C 6 . Pod (legume) which is 



Oblong, flat, about 2 in. broad and curved. . 27. GYMNOCLADUS CANADENSIS. 

 Linear, twisted and contorted, about 1 in. broad. 



28. GLEDITSCHIA TRIACANTHOS. 



c 7 . Pome, globular 30. PYRUS MALUS. 



2 . Dehiscent pericarp. 

 c. Subglobose, and 



d. Coriaceous, dehiscent by 



2-3 valves and containing one or very few large seeds with smooth shin- 

 ing coat and a large scar (^Esculus), fruit prickly and leaflets 7. 



6. ^ESCULUS HlPPOCASTANUM. 



4 valves 



Parting the whole length, nut thick, hard, whitish and embyro edible. 



36. CARYA ALBA. 

 Parting half way and containing a thin-shelled, whitish and bitter 



nut 37. CARYA AMARA. 



<? 2 . Covered with spines; dehiscent by 4 valves. 



Nuts sharply three-angled, 2 together, involucre soft-prickly. 



16. FAGUS FERRUGINEA. 



Nuts subovoid, flattened, 1-3 together, involucral spines very sharp and 

 hard .40. CASTANEA VESCA, var. AMERICANA. 



