FAMILY KEY 1 3 



GROUP 4 — Trees with alternate leaves 



A. Leaves compound. Sorbus in Malaceae (p. 132) 



AA. Leaves simple. 

 B. Leaves coriaceous, evergreen. 

 C. Bark conspicuously reddish, peeling off in great patches; leaves oval or ellip- 

 tical, 7-1S cm. long; fruit a red berry. Arbutus in Ericaceae (p. 171) 

 CC. Bark not conspicuously reddish, not conspicuously peeUng off; leaves vari- 

 ous. 

 D. Leaves oblanceolate, 5-10 cm. long, 12-25 mm. wide, either entire or 

 serrate near the tip. Myricaceae (p. 73) 

 DD. Leaves not oblanceolate, often not as above in size or margin. 

 E. Leaves either cuneate-obovate, or else lanceolate and oidy 1-2,5 cm. long; 

 fruit akenes, with hairy tails 5-15 cm. long. Cercocarpus in Rosaceae (p. 125) 

 EE. Leaves not cuneate-obovate, not lanceolate unless more than 2.5 cm. 

 long; fruit not akenes, not tailed. 

 F. Leaves lanceolate, acute, entire, glabrous on both sides, not scurfy; 

 fruit a drupe about 2 cm. long. Lauraceae {p. 104) 

 FF. Leaves either not lanceolate or scurfy beneath if so; fruit dry, a nut 

 (acorn) in a cup, or else several nuts in a long prickly involucral cover. 



Fagaceae (p. 75) 

 BB. Leaves mostly herbaceous, deciduous. 

 G. Bark plainly splitting around the trunk rather than longitudinally. 

 H. Flowers in aments or conelike clusters, sessile; fruits grouped into a dry 

 conelike mass; terminal winter buds none. Betulaceae (p. 73) 



HH. Flowers in racemes or umbels, pedicelled; fruits separate, fleshy, drupes ; 

 terminal winter buds present. Amygdalaceae (p. 134) 



GG. Bark splitting longitudinally. 



I. Staminate flowers in aments and sometimes the pistillate flowers also. 

 J. Fruit an aggregate berry, blackberry-like. Morus in Moraceae (p. 76) 

 JJ. -Fruit dry, nutlike or conelike. 

 K. Fruit a cup containing an acorn; leaves often deeply lobed or cleft; 

 primary lateral veins extending into the teeth; winter buds with more 

 than 2 scales; terminal winter buds present. Fagaceae (p. 75) 



KK. Fruits in a conelike or ament-like cluster; leaves in most species 

 shallowly if at all lobed; bud scales i to many; terminal winter buds present 

 or none. 



L. Primary lateral leaf veins extending into the teeth or lobes; seed a 

 winged nutlet; calyx present; bracts thick in fruit. Betulaceae (p. 73) 

 LL. Primary lateral leaf veins arching and uniting within the margins; 

 ■ seed hairy; calyx none; bracts thin in fruit. Salicaceae (p. 70) 



n. Flowers not in aments. 

 M. Leaves ovate, somewhat falcate, distinctly oblique at base, coarsely ser- 

 rate, 3-veined from the base. Celtis in Ulmaceae (p. 76) 

 MM. Leaves not as above in all the characters mentioned. 

 N. Fruit dry, wing-margined. Ulmus in Ulmaceae (p. 76) 

 NN. Fruit fleshy, not even angular. 

 O. Petals 6 mm. or more long; stamens many; leaves usually distinctly 

 serrate; winter buds covered with scales. Malaceae (p. 132) 



