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 1b, 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 =f.a.gACEAE=, p. 23.

127c. Pith cylindrical --128.

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

128b. Leaves coa.r.s.ely or doubly serrate 41a, in =ROSACEAE=, p. 54.

129a. Leaves coa.r.s.ely 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.

131a. Leaves with glands on the petiole or at the base of the leaf-blade --132.

131b. Leaves with small dark glands on the upper side of the mid-vein 42a, in =ROSACEAE=, p. 54.

131c. Leaves without glands --133.

132a. Willows; with usually slender leaves, frequently conspicuous broad stipules, and lateral buds protected by a single external bud-scale 13, in =SALICACEAE=, p. 20.

132b. Plums and cherries; with leaves lanceolate or broader, and stipules minute and falling early in the season; lateral buds with more than one bud-scale 30, in =ROSACEAE=, p. 54.

133a. With stipules or with stipular scars indicating where stipules have been detached --134.

133b. Without stipules or stipular scars --138.

134a. With three bundle-scars in each leaf-scar --135.

134b. With one bundle-scar in each leaf-scar --136.

135a. Willows; usually with slender leaves and twigs and frequently with large conspicuous stipules; lateral buds covered by a single external bud-scale 13, in =SALICACEAE=, p. 20.

135b. Juneberries; with oblong or ovate leaves and small stipules which fall early; lateral buds with more than one external scale 42b, in =ROSACEAE=, p. 55.

136a. Leaves mostly entire, only a few here and there with low teeth 1a, in =AQUIFOLIACEAE=, p. 69.

136b. Leaves sharply toothed --137.

137a. Axillary buds superposed, i. e., with a second one just above the first 1b, in =AQUIFOLIACEAE=, p. 69.

137b. Axillary buds not superposed 2b, in =RHAMNACEAE=, p. 71.

138a. Leaves with purple petioles, which are at least one-fourth as long as the blade 1a, in =AQUIFOLIACEAE=, p. 69.

138b. Leaves short-petioled or sessile --139.

139a. Stems erect and straight, unbranched or with very few branches 27, in =ROSACEAE=, p. 53.

139b. Stems more or less crooked and freely branched, making a spreading shrub 25, in =ERICACEAE=, p. 86.

--140--

140a. Flowers appearing in autumn, after the leaves have fallen =HAMAMELIDACEAE=, p. 51.

140b. Flowers appearing in spring, before the leaves have opened --141.

141a. Flowers in catkins, without brightly colored or petal-like parts --142.

141b. Flowers not in catkins, either with or without brightly colored or petal-like parts --149.

142a. Leaves 2-ranked, as shown by the arrangement of buds and leaf-scars in two longitudinal rows, so that the third bud is directly over the first --143.

142b. Leaves and leaf-scars not 2-ranked --146.

143a. Bundle-scars three in each leaf-scar --144.

143b. Bundle-scars several in each leaf-scar 2b, in =URTICACEAE=, p. 23.