24 Field Manual 



1-J. Twig- without complete stipular rings. 18. 



Hi. Leaf scar surroundinii: the axillary hnd, terminal bud 



self-pruned; wood with pr<iniinent nu'diillary rays. 



Plantanus. (47\ 

 lt>. Leaf scar not snrroundiii.u the a.xillary hud, terminal 



hud not self-pruned; huds enclosed in the large 



connate stipules. 17. 

 li. r.U(L glabrous; twigs brown; pith diaphragmed; leaf 



scars oval or circular; hark spicy-aromatic. 



Liriodendron. {1:{). 



17. r.uds downy, or if glabrous then the twigs red; pith 



with or without diaphragms; leaf scars U-shaped, 

 oval, or circular: bark usuall}- aromatic. 



Magnolia, (li) 



18. With thorn.N. prickles, or spines; or with spur-like 



branches ending in thorns. 1!». 



18. Without thorns, prickles or spines, but .some may have 



thorn-like stunted branches. 'lil. 

 1!'. With stipular spines, a ])air for each leaf scar. 2li. 



19. Twigs with • typical lateral thorns, without terminal 



thorns. 21. 

 19. With thorns at the ends of branches or with spur-like 

 branches ending in thorns, and in additifm axillary 

 thorns may be present. 22. 



19. Stems or twigs with prickles; leaf scar extending 



nearly around the stem, with about 20 bundle scars; 

 pith large. Aralia. (78). 



20. Leaf scar covering the two or more superposed 



axillary buds. Robinia. (88). 



20. Leaf scar below the axillary buds; buds reddish, 



pubescent. Zanthoxylum. (17). 



21. . With thorns beside the axillar}- buds; normally one 



for each leaf axil, becoming gradually smaller 

 toward the tip of the twig, terminal bud absent. 



Toxylon. (^52) 



21. 'riiorns axillary, large, rarely branched except on the 



main trunk; usually with two lateral buds at the 



base W'hich may develop as twigs; numerous axils 



without thorns. Crataegus. (20). 



