KEY, BASKD UPON FRUIT. 9 



Purple black, 5-seeded, in umbels 8. ARALIA SPINOSA. 



lied or purplish, 4-8-seeded, axillary 52. ILEX OPACA. 



(I 2 . Not crowned with calyx-teeth but scaly-bracted beneath, 2-5 seeded, blu- 

 ish-black 25. JUNIPERUS VlRGINIANUS. 



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

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



(Quercus), acorn borne 



e. On the new wood of the season (Leucobalanus), cup 

 /. About | enveloping the small, ovoid nut; scales thin and appressed. 



68. Q. MUHLENBERGII. 



/ 2 . About ^ enveloping the nut 



Thick, scales very roughly tubercled, edge of cup rather inturned 



after shedding the nut; nut usually long-ovoid 38. Q. ALBA. 



Thinner, edges flaring out after shedding the nut, scales thinnish; 



peduncles shorter than petioles 67. Q. PRINUS. 



/ 3 . About \ enveloping the nut; scales loosely appressed; peduncles 



longer than petioles 66. Q. BICOLOR. 



/ 4 . More than 4- enveloping the large, broad-ovoid nut; scales very loosely 



appressed and making a mossy fringe 39. Q. MACROCARPA. 



e 2 . On wood of the preceding season (Melanobalanus); cup 



Saucer-shaped, very shallow, enveloping the nut, scales very closely 



appressed 15. Q. RUBRA. 



Top-shaped, \ enveloping the acorn; scales thin and coarse. 



69. Q. COCCINEA. 



(P. Club-shaped, short, surrounded with stiff hairs, tipped with the persistent 

 recurved style and arranged in globular heads. 



13. PLATANTJS OCCIDENTALS. 

 f/ 3 . Acheuium-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. 

 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 pe- 

 duncle (Tilia] 3. T. AMERICANA. 



e 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; capsules 

 d. Cartilaginous. 



e. Sunken at insertion of pedicel, globular and 



Large, 1 in. or more, distinctly 5-celled 30. PYRUS MALUS. 



Small, more or less 10-celled 59. AMELANCHIER CANADENSIS. 



e 2 . Not sunken at insertion of pedicel, pyriform 57. PYRUS COMMUNIS. 



rf 2 . Not cartilaginous, 1-5 bony seeds " 58. CRATAEGUS PUNCTATA. 



.v0 8 . Berry, large, globose with persistent thickish calyx at the base. 



61. DlOSPYROS VlRGINIANA. 



. Dehiscent pericarp. 

 C. Subglobose, and 



(I. Coriaceous, dehiscent by 



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

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



6. J3SCULUS HlPPOCASTANUM. 



e' 2 . 4 valves (Carya). 

 /. Parting the whole length; nut ridged and shell thick. 



Nut flattish-globular, scarcely 1 in. in length 36. C. ALBA. 



Nut globular-oval 1 in. or more in length 64. C. SULCATA. 



/*. Not parting freely to the base; nut quite smooth. 



Very thin-shelled, small, and kernel very bitter 37. A. AMARA. 



Thick-shelled and kernel only moderately brittle 65. C. PORCINA. 



rf 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. 



2 



