18 



Leaves less than 1.5 dm. (6 inches) long, flow- 

 ers in clusters. 



Bark and leaves aromatic Laurace.e 163 



Bark and leaves not aromatic. 



Fruit dry, an acorn Qitercus imbricabia 



IN Fagace* 119 



Fruit fleshy. 



Fruit with one seed, stone cylindrical. .Nyssa in 



C<5rnace-e 259 



Fruit with more than one seed, 



rarely one, seeds flat Ebenace.e 205 



B. Leaves finely serrate, coarsely toothed or lobed. 



C. Leaves with one primarj' vein. 



Bark and leaves aromatic Laurace.e 163 



Bark and leaves not aromatic. 



Staminate and pistillate flowers and fruit in catkins. 

 Scales of winter buds 2, ovary many-seeded, 



seeds with a tuft of hairs at the summit. . . .Salix in 



Salicace.b 34 



Scales of ^\inter buds more than 2, ovar.v 1- 

 seeded, seeds T\'ithout a tuft of hairs at the 



summit Betulace^e 78 



Staminate and pistillate flowers and fruit not in 

 catkins. 

 Fruit dr.v. 



Fruit a samara Ulmus in Ulmace^ 137 



Fruit not a samara. 



Bark smooth; fruit spiny Fagace.e 92 



Bark furrowed; fruit a smooth capsule. . . .Ericacejii 263 



Fruit fleshy. 



Flowers more than 8 mm. (J. 3 inch) broad, 

 fruit edible, apple-like. 

 Trees mostly with thorns, fruit with rem- 

 nant of calyx at apex of fruit, normally 



with more than 1 seed Malace.e 171 



Trees without thorns, fruit with no rem- 

 nant of calyx at the apex, fruit a 1- 



seeded edible drupe Amygdalace^. 216 



Flowers less than 8 mm. (J:3 inch) across, 



fruit a non-edible drupe Cornace^ 259 



C. Leaves with more than 1 primary vein. 

 Staminate and pistiUato flowers in catkins. 



Fruit dry Populus in 



Salicacea: 45 



Fruit flesliy Morus in 



Morace.'e 151 



Staminate and pistillate flowers not in catkins. 

 Pistillate and staminate flowers separate. 



Leaves 3-nerved at the base, fruit a 1-seeded 



drupe Celtis in 



Ulmace^e 146 



