XVlii ANALYTICAL KEY TO THE FAMILIES 



/Juice watery. 



Stipules present. 



h Primary veins extending straight to the teeth. 



Pasania and some species of Quercus in Fagaceae (pp. 224, 



226). 



hh Primary veins arching and united within the margin. 

 Leaves 3-nerved from the base. 



Ceanothus in Rhamnaceae (p. 665). 

 Leaves not 3-nerved. 

 Leaves acute. 

 Leaves sinuately dentate, with few spiny teeth, glabrous. 



Ilex opaca in Aquifoliaceae (p. 614). 

 Leaves serrate. 



Vauquelinia, Heteromeles,and Prunus Carolin- 

 iana and Prunus ilicif olia in Rosaceae (pp. 349, 



358, 527, 530). 



Leaves obtuse, sometimes mucronate. 

 Leaves spinose-serrate, glabrous. 



Rhamnus crocea in Rhamnaceae (p. 662). 

 Leaves crenate (often entire), oval to oblong. 



Hex vomitoria in Aquifoliaceae (p. 616). 

 hkh Primary veins extending straight to the teeth. 



Cercocarpus in Rosaceae (p. 504). 

 gg Stipules wanting. 



Leaves resinous-dotted, aromatic. Myricaceae (p. 146). 



Leaves not resinous-dotted, crenately serrate, gradually narrowed 

 into short stout petioles ; bark red-brown. 



Gordonia Lasianthus in Theaceae (p. 678). 

 //"Juice milky. 



Hippomane and Gymnanthes in Euphorbiaceae (pp. 598, 599). 

 ee Leaves entire (rarely sparingly toothed on vigorous branchlets). 

 i Stipules present. 

 j Stipules connate, at least at first. 



Stipules persistent, forming a sheath surrounding the branch above 

 the node; leaves obtuse. Polygonaceae (p. 311). 



Stipules deciduous, enveloping the young leaf before unfolding. 

 Leaves ferrugineous-tomentose beneath. 



Magnolia fcetida in Magnoliaceae (p. 316). 

 Leaves glabrous beneath, with milky juice. 



Ficus in Moraceae (p. 308). 

 jj Stipules free. 

 k Juice milky. 



Drypetes and Gymnanthes in Euphorbiaceae 



(pp. 595, 599). 

 kk Juice watery. 



I Leaves obtuse or emarginate at the apex. 



Leaves with ferrugineous scales beneath, their petioles slender. 



Capparidaceae (p. 338). 

 Leaves without ferrugineous scales. 



Leaves rarely 2'-3' long, standing on the branch at acute 



angles. Chrysobalanus in Rosaceae (p. 532). 



Leaves rarely more than 1' long, spreading (sometimes 3-nerved). 



Ceanothus spinosus in Rhamnaceae (pp. 667). 



