io A Bud and Twig Key 



e2. Without band of tomentum between leaf-scar 

 and buds, terminal bud about one- fourth inch 

 long, pith usually light brown, twig reddish 

 brown slightly pubescent. Plate III. 



* /. nigra Linn. 

 * 7. rupestris Engelm. 



d2. Pith nearly white solid, bundle-scars many scatter- 

 ed, axillary buds small quite regular and symmetri- 

 cal, leaf-scars obscurely three-lobed, terminal buds 

 one-half inch long compressed, usually two scales 

 visible. 



ei. Terminal bud bright yellow, leaf -scar small. 



Hicoria minima (Marsh) Britton. 



e2. Terminal bud covered with a dark brown glandu- 

 lar pubescence,f leaf-scar large with thin mem- 

 branaceous border around it. 



Hicoria pecan Britton. 



d$. Pith white solid often with woody transverse par- 

 titions, bundle-scars about five in a U-line, axillary 

 buds small oval, leaf-scars crescent-shaped narrow, 

 terminal buds very narrow about one-fourth inch 

 long, no scales distinct, very dark brown densely 

 silky, twigs small, branchlets with longitudinal shal- 

 low grooves. 



Aslmma triloba (Linn.) Dunal. 



bs. Bud at end of twig quite regular in outline but unsym- 

 metrical in form, scales not felty. 



* Distinction between these two species is rather difficult from twigs 

 alone. 7. rupestris has larger terminal buds, usually between one-fourth 

 and one-half inch long, pubescence on twigs remains until the second year, 

 branches in their fourth year are nearly white. 7. nigra has terminal buds 

 usually a little less than one-fourth inch long, the branchlets in the second 

 year are glabrous. 



f United States Forest Service Bulletin 80. 



