FAMILY KEY 



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, 7-15 cm. long; fruit a red berry. Arbutus in ERICACEAE (p. 171) 

 CC. Bark not conspicuously reddish, not conspicuously peeling 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 only 1-2.5 cm. long; 



fruit akenes, with hairy tails 5-15 cm. long. Cercocarpus in ROSACE AE (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, flesh>, 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) 



