KEY TO GENERA 29 



214. Buds solitary. . . Rhamnus, p. 143 



214. Buds superposed. . . Ilex, p. 134 



215. Leaf-scars on large leaf-cushions. 217 



215. Not as above. 216 



216 Twigs prominently angled or grooved. . . Gytisus, p. 129 



216. Not as above. 218 



217. Buds ellipsoid, twigs rounded. . . Potentilla, p. 115 



217. Not as above. . . Spiraea , p. 105 



218, Bud-scales 2, bundle-trace semicircular . . . Diospyros, p. 178 



218. Not as above. 219 



219. Leaf-scars about as high as wide. 220 



219. Leaf-scars wider than high. 225 



220. Twigs aromatic, green. . . Sassafras , p. 98 



220. Not as above. 221 



221, Terminal bud not enlarged, or absent. 222 



221. Terminal bud larger than the lateral buds. 223 



222. Twigs brown or red. , . Oxydendrum, p, 171 



222. Twigs gray. . . Lyonia, p. 170 



223, Outer bud-scales as long as the bud. . , Clethra, p. 161 



223. Outer bud-scales shorter than the bud. 224 



224. Bark shredding; capsules bristly. . . Menziesia, p. 167 



224. Not as above. . . Rhododendron , p. 163 



225. Soft- wooded, or aromatic. 226 



225, Neither soft-wooded nor aromatic. 227 



226. Soft-wooded; not aromatic. , , Ceanothus , p. 145 



226. Aromatic; not soft-wooded. , , Sassafras, p. 98 



227. With stipules or stipule-scars. 228 



227. Without stipules or stipule-scars. 229 



228. Buds sometimes superposed. . , Ilex„ p, 134 



228. Buds not superposed. , . Spiraea , p. 105 



229. Bud-scales 2, twigs glaucous. , . Nemopanthus, p. 135 



229. Not as above. 230 



230, Buds ovoid or oblong, 231 

 230, Buds globose or nearly so. 234 



