XX ANALYTICAL KEY TO THE FAMILIES 



Leaves eniarf^-inate ; petioles slender, mfoxis-tonientiilose. 

 Mimusops ill Sapotaceae (p. 740). 

 Leaves obtuse at the apex ; petioles stout, grayish-tomen- 

 tulosc or j^labrons. 



Rhus integiifolia in Anacardiaceae (p. 609). 

 00 Leaves cuneate at the base. 



Petioles slender, ^' long. Bourreria in Borraginaceae (p. 784). 

 Petioles short and stout. 



Leaves coriaceous, with thick revolute margins {sometimes oppo- 

 site). Theophrastaceae (p. 735). 

 Leaves subcoriaceous, slightly revolute. 



Leaves oval to obovate ; branches spreading. 



Vaccinium in Ericaceae (p. 731). 

 Leaves obovate-oblong to oblong--lanceolate ; branches upright 

 {sometimes decirfuous in Cyrilla). Cyrillaceae (p. GIO). 

 --Leaves deciduous. 



*+Leaves conspicuous. 



a Leaves entire, sometimes 3 or 4-lobed. 

 b Stipules present. 



Juice milky. Moraceae (p. 302). 



Juice watery. 



Stipules connate, enveloping the young leaves. Magnoliaceae (p. 315). 

 Stipules distinct. 



Branches spineseent, leaves glandular, caducous (crenateJy serrate on 

 vigorous shoots). Dalea in Leguminosae (p. 570). 



Branches not spineseent ; leaves without glands. 

 Winter-buds with a single pair of connate scales. 



Salix in Salicaceae (p. 166). 

 Winter-buds with several pairs of imbricate scales ; branchlets without 

 terminal buds. 



Celtis Mississippiensis in Ulmaceae (p. 300). 

 bb Stipules wanting. 



c Leaves broad, oval to lanceolate. 



Branchlets bright green and lustrous for the first 2 or 3 years ; leaves 

 sometimes 3-lobed, aromatic. Sassafras in Lauraceae (p. 335). 



Branchlets brown or gray. 

 Leaves acute or acuminate. 



Leaves 10'-12' long, obovate-oblong, acuminate, glabrous, emitting a 

 disagreeable odor. Asimina in Anonaceae (p. 326). 



Leaves smaller. 



Leaves glabrous, or pubescent below at maturity. 



Petioles very slender l'-2' long ; leaves elliptic, acuminate. 



Cornus alternifolia in Cornaceae (p. 717). 

 Petioles short. 



Branchlets without lenticels, light reddish brown. 



Elliottia in EricaceaB (p. 719). 

 Branchlets with small lenticels. 

 Branchlets with terminal buds. 



Nyssa in Cornaceae (p. 707). 

 Branchlets without terminal buds. 



Diospyros Virginiana in Ebenaceae (p. 749). 

 Leaves tomentose below, elliptic to lanceolate-oblong. 



Leitneriaceae (p. 150). 



