KEY, BASED UPON FLO WEES. 



/ 8 . Corolla not present in the fertile flower ; fruit with usually 4-valved 



epicarp (Carya) which is 

 g. Thick ; valves separating to base ; bark. 

 h. In loose plates, leaflets. 



5, smoothish ; nut small 36. C. ALBA. 



7-9; nut large 64. C. SULCATA. 



h*. Close, leaflets 7-9, tomentose 90. C. TOMENTOSA. 



gr 2 . Thin ; bark close ; nut. 

 h. Quite smooth, small, thin-shelled, leaflets. 



5-7; kernel edible 91. C. MICROCARPA. 



7-9; kernel very bitter 37. C. AMARA. 



W. More ridged, larger, thicker- shelled ; leaflets 5-9. 



65. C. PORCINA. 



e 2 . Fertile flowers 1-3 together, invested wholly or partly with an involucral 



covering; leaves simple (Cupuliferce). 

 f. Involucre valveless, cup -like, composed of many scales and only partly 



inclosing the one nut, i. e., acorn (Quercus). 

 g. Leaves with teeth and lobes obtuse or rounded (not bristle pointed); 



acorns maturing first year (and hence on new wood) and leaves 

 h Oblong, sinnate-pinnatifid, nut immersed in the tubercled cup. 



38. Q. ALBA. 



/fc 2 . Lyrate-pinnatifid, nut -J or more immersed. 



Peduncles shorter than petioles 39. Q. MACROCARPA. 



Peduncles longer than petioles 66. Q. BICOLOR. 



h?. Obovate and deeply sinnate-lobed, the two lobes near the summit 



much the largest 93. Q. OBTUSILOBA. 



Oblong, undulately crenate-toothed, peduncles shorter than 



petioles 67. Q. PRINUS. 



Lanceolate-oblong, sharply undulate-toothed; acorn small. 



68. Q. MUHLEXBERGII. 



gr 2 . Leaves with teeth and lobes acute and bristle-pointed; acorns matur- 

 ing the second year (and hence on old wood); leaves 

 h. Moderately pinnatifid ; cup very shallow and saucer-shaped; 



scales fine 15. Q. RUBRA. 



h 9 . Deeply pinnatifid; lobes 



i. Rather broad; inner bark yellowish 93. Q. TINCTORIA. 



i 2 . Narrow; sinuses broad and rounded; acorn 



Ovoid-oblong, -J invested in a coarse-scaled cup. 



69. Q. COCCINEA. 

 Flattened-globular, $ invested in fine-scaled cup. 



94. Q. PALUSTRIS. 



f*. Involucre 2-4-valved, becoming hard and prickly and inclosing 1-3 

 sweet, edible, flattened, subglobose nuts ; sterile flowers in catkins. 



40. CASTANEA VESCA. 

 / 3 . Involucre 4-valved and inclosing two 3-cornered, edible nuts. 



16. FAGUS FERRUGINEA. 

 e 3 . Fertile flowers in short catkins ; nuts small and acheniuin-like ; sterile 



flowers destitute of calyx ; leaves simple. 

 /. Nutlet inclosed in a bladder-like bag 41. OSTYRA VIRGINICA. 



