62b. Stem dec.u.mbent or prostrate --63.

63a. Leaves round, ovate, or kidney-shape, rounded at the base, crenate or lobed 12a, in =SAXIFRAGACEAE=, p. 50.

63b. Leaves of a narrower shape, entire, tapering toward the base --64.

64a. Princ.i.p.al leaves 2-3 cm. long 1a, in =ONAGRACEAE=, p. 78.

64b. Princ.i.p.al leaves 1 cm. long or less --65.

65a. Petals present =ELATINACEAE=, p. 74.

65b. Petals none =CALLITRICHACEAE=, p. 68.

--66--

66a. Plants of the composite type, with several or many small flowerets closely aggregated into a dense head surrounded or subtended by a calyx-like involucre of small bracts --67.

66b. Flowers solitary or variously cl.u.s.tered, but not in involucred heads --70.

67a. Involucre of 4 conspicuous white bracts, much larger than the small flower-cl.u.s.ter 4a, in =CORNACEAE=, p. 83.

67b. Involucral bracts green or somewhat colored --68.

68a. Stem more or less p.r.i.c.kly =DIPSACACEAE=, p. 112.

68b. Stem and leaves not p.r.i.c.kly --69.

69a. Stem square; foliage aromatic when crushed =l.a.b.i.aTAE=, p. 95.

69b. Stem not square; foliage not with the odor of mint =COMPOSITAE=, p. 113.

70a. The conspicuous portion of the perianth[1] composed of separate parts --71.

70b. The conspicuous portion of the perianth[1] composed of united parts --97.

71a. Stem-leaves compound, or cleft to the very base --72.

71b. Stem-leaves simple --78.

72a. Stamens more than 10 in each flower --73.

72b. Stamens 5-10 in each flower --75.

73a. Ovary 1 in each flower 2a, in =PAPAVERACEAE=, p. 41.

73b. Ovaries several in each flower --74.

74a. Leaves pinnately compound 68a, in =ROSACEAE=, p. 57.

74b. Leaves palmately compound =RANUNCULACEAE=, p. 35.

75a. Stamens 6 31, in =CRUCIFERAE=, p. 44.

75b. Stamens 5 or 10 --76.

76a. Leaflets reverse heart-shape; flowers yellow =OXALIDACEAE=, p. 64.

76b. Leaflets not reverse heart-shape; flowers white, greenish, or pink --77.

77a. Flowers greenish or white, about 2 mm. broad =ARALIACEAE=, p. 80.

77b. Flowers 5 mm. broad or larger =GERANIACEAE=, p. 64.

78a. Juice milky --79.

78b. Juice not milky --80.

79a. A 3-lobed ovary with 3 short styles visible in some of the flowers =EUPHORBIACEAE=, p. 66.

79b. Ovaries 2 in the center of each flower (sometimes concealed by other organs); sepals and petals each 5 --104.

80a. Perianth with one circle of parts only --81.

80b. Each flower with both calyx and corolla --82.

81a. Stem prostrate; flowers only 2 mm. broad =AIZOACEAE=, p. 31.

81b. Stem erect; flowers at least 20 mm. wide 4a, in =CORNACEAE=, p. 83.

82a. Petals 2 or 4 --83.

82b. Petals 3 22, in=LILIACEAE=, p. 12.

82c. Petals 5 or 6 --84.

83a. Leaves with 3-5 princ.i.p.al veins =MELASTOMACEAE=, p. 77.

83b. Leaves with 1 princ.i.p.al mid-vein =ONAGRACEAE=, p. 78.

84a. Leaves palmately lobed --85.

84b. Leaves entire or toothed, or with 1-2 small lobes near the base only --86.

85a. Petals entire or notched at the end =GERANIACEAE=, p. 64.

85b. Petals conspicuously fringed 23b, in =SAXIFRAGACEAE=, p. 51.

86a. Ovary 1 --87.