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.