xxx KEYS LEAVES ALTERNATE 



287. Lowest scale central over the leaf -scar: pith 5-angled, 



sometimes spongy. p. 9. Populus. 



Without this combination of characters. 288. 



288. With resin-glands or blisters, at least in sheltered 



places. 289. 

 Not resinous-glandular. 290. 



289. Stipule-scars elongated: resin in blisters. p. 23. Betula. 

 Stipule-scars minute or lacking. p. 13. Myrica. 



290. Buds distinctly stalked below their lowest scales. 291. 

 Buds not stalked except as they begin to develop. 295. 



291. Leaf-scars 2-ranked: buds pubescent. 293. 

 Leaf-scars in more than 2 ranks. 292. 



292. Spicy-aromatic. p. 72. Benzoin. 

 Not aromatic. p. 25. Alnus. 



293. Bark flaking: buds often black. p. 86. Parrotia. 

 Buds not exfoliating. 294. 



294. Fruit in elongated clusters. p. 87. Fothergilla. 

 Partly developed fruit in sessile groups, p. 88. Hamamelis. 



295. Pith 3-sided or much flattened. 296. 



Pith neither 3-sided nor greatly flattened. 297. 



296. Bud-scales scarcely meeting. p. 25. Alnus. 

 Bud-scales overlapping. p. 23. Betula. 



297. Twigs 3-Hbbed below the (usually stipulate) 



leaf-scars. 298. 



Twigs not sharply 3-ribbed from the leaf-scars 

 when fresh. 307. 



298. Twigs green or red, slender: small shrubs. 299. 

 Without this combination of characters. 300. 



299. Twigs green: buds solitary. p. 113. Kerria. 

 Twigs red: buds superposed. p. 93. Stephanandra. 



300. Leaf-scars fringed: buds superposed. p. 137. Cercis. 

 Leaf-scars not fringed or else buds not superposed. 301. 



301. Buds superposed. 302. 

 Buds not superposed. 303. 



