50a. Juice somewhat milky; lateral buds visible 2b, in =URTICACEAE=, p. 23.
50b. Juice not milky; lateral buds covered by the base of the petiole =PLATANACEAE=, p. 51.
51a. Leaves with 4 large entire lobes; stem marked with a ring at each node =MAGNOLIACEAE=, p. 40.
51b. Leaves with many lobes; stem not ringed 1b, in =f.a.gACEAE=, p. 22.
--52--
52a. For specimens bearing leaves only --53.
52b. For specimens bearing flowers only --140.
52c. For specimens with both leaves and flowers --155.
53a. Leaves narrow, needle-like or scale-like, mostly evergreen --54.
53b. Leaves broader, flat or rolled, but not needle-like or scale-like --56.
54a. Foliage densely gray-p.u.b.escent; low bushy shrubs with yellow flowers 2a, in =CISTACEAE=, p. 74.
54b. Foliage green --55.
55a. Leaves opposite or whorled =PINACEAE=, p. 1.
55b. Leaves scattered on the stem =TAXACEAE=, p. 2.
56a. Twining or climbing vines --57.
56b. Not climbing or twining --66.
57a. Th.o.r.n.y vines --58.
57b. Not th.o.r.n.y --60.
58a. Climbing by tendrils at the base of the leaves 4b, in =LILIACEAE=, p. 11.
58b. Tendrils none --59.
59a. Leaves simple 5a, in =SOLANACEAE=, p. 100.
59b. Leaves compound 8a, in =ROSACEAE=, p. 52.
60a. Leaves compound --61.
60b. Leaves simple --63.
61a. Leaves with 5 leaflets 1a, in =VITACEAE=, p. 71.
61b. Leaves with 3 leaflets --62.
62a. Plant climbing by tendril-like leaf-stalks 1a, in =RANUNCULACEAE=, p. 35.
62b. Plant climbing by hold-fast roots 5b, in =ANACARDIACEAE=, p. 69.
63a. Leaves opposite 5a, in =CAPRIFOLIACEAE=, p. 110.
63b. Leaves alternate --64.
64a. Plants climbing by tendrils 1b, in =VITACEAE=, p. 71.
64b. Twining plants --65.
65a. Leaves ovate-oblong, attached by the base 1a, in =CELASTRACEAE=, p. 69.
65b. Leaves almost round, peltate near the edge =MENISPERMACEAE= p. 40.
66a. Leaves opposite --67.
66b. Leaves alternate --84.
67a. Leaves compound --68.
67b. Leaves simple --69.
68a. Leaflets 3 =STAPHYLEACEAE=, p. 69.
68b. Leaflets 7 or more 1a, in =CAPRIFOLIACEAE=, p. 109.
69a. Leaves palmately veined, or at least with a pair of prominent lateral veins from the base --70.
69b. Leaves pinnately veined --72.
70a. Leaves not lobed 1b, in =RHAMNACEAE=, p. 71.
70b. Leaves more or less lobed --71.
71a. Leaves with stipules 22a, in =CAPRIFOLIACEAE=, p. 111.
71b. Leaves without stipules 2a, in =ACERACEAE=, p. 70.
72a. Leaves serrate --73.
72b. Leaves entire --77.
73a. Stem th.o.r.n.y 1b, in =RHAMNACEAE=, p. 71.
73b. Stem not th.o.r.n.y --74.