KEY, BASED UPON FLOWERS. 5 



/. 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, sinuate-pinnatifid, nut immersed in the tubercled cup. 



38. Q. ALBA. 



h*. Lyrate-pinnatifid, nut or more immersed. 



Peduncles shorter than petioles 39. Q. MACROCARPA. 



Peduncles longer than petioles 66. Q. BICOLOR. 



h 3 . Obovate and deeply sinuate-lobed, the two lobes near the summit 



much the largest 93. Q. OBTUSILOBA. 



h*. Oblong, undulately crenate-toothed, peduncles shorter than 

 petioles ; acorn 



Less than 1 in. in length 67. Q. PRINUS. 



More than 1 in. in length 116. Q. MICHEAUXII. 



& 5 . Lanceolate-oblong; sharply undulate-toothed ; acorn small. 



68. Q. MUHLENBERGII. 



h*. Elliptical or oblong, evergreen 117. Q. VIRENS. 



/j, 7 . Obovate-spatulate, partly deciduous 118. Q. AQUATICA. 



h 8 . Oval-obovate, sinuses narrow and lobes broad. 



136. Q. GARRYANA. 



7t 9 . Orbicular-oblong, sinuately-spinous-toothed, subpersistent. 



138. Q. AGRIFOLIA. 



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?. Deeply pinnatifid; lobes 



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



i 2 . Narrow; sinuses broad and rounded; acorn 



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



69. Q. COCCINEA. 

 Flattened-globular, invested in fine-scaled cup. 



94. Q. PALUSTRIS. 



h 3 . Serrate-dentate, persisistent 138. Q. AGRIFOLIA. 



/'. Involucre 2-4-valved, becoming hard and prickly and inclosing 1-3 

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

 leaves 



Deciduous 40. CASTANEA VESCA. 



Evergreen 139. CASTANOPSIS CHRYSOPHYLLA. 



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



16. FAGUS FERRUGINEA. 



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

 flowers destitute of calyx ; leaves simple. 



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



/*. Nutlet not inclosed but subtended by an enlarged leafy bract. 



42. CARPINUS CAROLINIANA. 



d?. Both staminate and pistillate flowers in catkins. 

 . Ovary and pod 2-celled, many-seeded. 



60. LlQUIDAMBAR STYRACIFLUA. 



