144a. Leaf-buds with only 1-3 visible bud-scales 10, in =BETULACEAE=, p. 22.

144b. Leaf-buds with more than 3 visible scales --145.

145a. Bark of the branches smooth and dark gray, the larger stems fluted with projecting longitudinal ridges 1b, in =BETULACEAE=, p. 21.

145b. Branches without projecting ridges 4, in =BETULACEAE=, p. 22.

146a. Pith 3-angled 8, in =BETULACEAE=, p. 22.

146b. Pith 5-angled 13b, in =f.a.gACEAE=, p. 23.

146c. Pith cylindrical --147.

147a. Visible outer bud-scales 2 or more --148.

147b. Buds with a single visible outer scale 13, in =SALICACEAE=, p. 20.

148a. Bundle-scars 3 in each leaf-scar =MYRICACEAE=, p. 20.

148b. Bundle-scars more than 3 in each leaf-scar 2b, in =URTICACEAE=, p. 23.

149a. Flowers dark red-purple, about 3 cm. wide =ANONACEAE=, p. 40.

149b. Flowers bright pink, irregular, about 1 cm. wide 3a, in =LEGUMINOSAE=, p. 58.

149c. Flowers white, with 5 conspicuous petals --150.

149d. Flowers greenish or yellowish, small, inconspicuous --152.

150a. Ovary 1, superior, i. e., in the center of the flower and not attached to surrounding parts 36, in =ROSACEAE=, p. 54.

150b. Ovary inferior, appearing as a swelling below the calyx at the apex of the pedicel --151.

151a. Flowers in racemes or solitary 42b, in =ROSACEAE=, p. 55.

151b. Flowers in flattened or rounded branching cl.u.s.ters 42a, in =ROSACEAE=, p. 55.

152a. Stems th.o.r.n.y 1a, in =RUTACEAE=, p. 65.

152b. Stems not th.o.r.n.y --153.

153a. Bark pleasantly aromatic when crushed; perianth with 6 parts --154.

153b. Bark not pleasantly aromatic; perianth with 4 short lobes =THYMELAEACEAE=, p. 77.

154a. Flowers in sessile lateral cl.u.s.ters 1a, in =LAURACEAE=, p. 41.

154b. Flowers in peduncled terminal cl.u.s.ters 1b, in =LAURACEAE=, p. 41.

--155--

155a. Leaves narrow, needle-like or scale-like, mostly evergreen --54.

155b. Leaves broader, flat or rolled, but not needle-like or scale-like --156.

156a. Twining or climbing vines --56.

156b. Not twining or climbing --157.

157a. Leaves opposite --158.

157b. Leaves alternate --165.

158a. Leaves compound --68.

158b. Leaves simple --159.

159a. Leaves broad, palmately lobed --160.

159b. Leaves not palmately lobed --161.

160a. Flowers greenish-yellow, in racemes or panicles 2a, in =ACERACEAE=, p. 70.

160b. Flowers white, in rounded or flattened cl.u.s.ters 22a, in =CAPRIFOLIACEAE=, p. 111.

161a. Flowers in close cl.u.s.ters, subtended by four large white petal-like bracts 4b, in =CORNACEAE=, p. 83.

161b. Flowers small, white, in dense spherical heads 1a, in =RUBIACEAE=, p. 108.

161c. Flowers not in dense heads, and not subtended by petal-like bracts --162.

162a. Petals separate from each other --163.

162b. Petals united with each other --164.

163a. Flowers dark purple-red 1b, in =CELASTRACEAE=. p. 69.

163b. Flowers bright yellow 1a, in =HYPERICACEAE=, p. 73.

163c. Flowers pink-purple; aquatic shrubs 1a, in =LYTHRACEAE=, p. 77.

163d. Flowers white 5, in =CORNACEAE=, p. 83.

163e. Flowers minute, greenish; twigs usually th.o.r.n.y 1b, in =RHAMNACEAE=, p. 71.

163f. Flowers small, yellowish; leaves silvery beneath =ELAEAGNACEAE=, p. 77.

164a. Stamens 2 1a, in =OLEACEAE=, p. 88.