xvii 



117a. Lateral veins curved forward and almost parallel to the mar- 

 gin of the leaf 2a, in CORNACEAE, p. 83. 

 117b. Lateral veins spreading 118. 



118a. Leaves lanceolate or linear, much longer than wide 119. 

 118b. Leaves ovate or elliptical 120. 



119a. Stem weak, spreading or trailing 5a, in SOLAN ACEAE, p. 100. 

 119b. Stems, or some of them, erect 3b, in LEGUMINOSAE, p. 58. 



120a. Leaves with purple petioles, which are at least one-fourth 

 as long as the leaf-blade la, in AQUIFOLIACEAE, p. 69. 



120b. Leaves with short petioles or sessile 



24c, in ERICACEAE, p. 86. 



121a. Lateral veins straight and parallel, mostly ending in the teeth 



of the leaf 122. 

 121b. Lateral veins not straight and parallel 129. 



122a. Leaves 2-ranked, i. e., in two longitudinal rows, with the 



third leaf directly above the first 123. 

 122b. Leaves not 2-ranked 127. 



123a. Leaves unsymmetrical, oblique at the base, i. e., with one side 

 of the leaf larger than the other HAMAMELIDACEAE, p. 51. 

 123b. Leaves symmetrical or nearly so at the base 124. 



124a. Lateral leaf-veins ending in the leaf-teeth 125. 

 124b. Lateral veins not ending in the teeth 



42b, in ROSACEAE, p. 55. 



125a. Bark smooth and fluted on the large stems 



Ib, in BETULACEAE, p. 21. 



125b. Bark rough or warty or glandular 126. 



126a. Leaves 4 cm. long or less 3a, in BETULACEAE, p. 22. 



126b. Leaves 5 cm. long or more 9b, in BETULACEAE, p. 22. 



127a. Pith 3-angled 6a, in BETULACEAE, p. 22. 



127b. Pith 5-angled 13b, in FAGACEAE, p. 23. 



127c. Pith cylindrical 128. 



128a. Leaves finely serrate 42b, in ROSACEAE, p. 55. 



128b. Leaves coarsely or doubly serrate 



41a, in ROSACEAE, p. 54. 



129a. Leaves coarsely or doubly serrate 130: 

 129b. Leaves simply serrate 131. 



130a. Leaves 2-ranked, i. e., in two longitudinal rows, with the 



third leaf directly over the first 9b, in BETULACEAE, p. 22. 



' 130b. Leaves not 2-ranked 41a, in ROSACEAE, p. 54. 



