67a. Involucre of 4 conspicuous white bracts, much larger than the 

 small flower-cluster 4a, in CORNACEAE, p. 83. 



67b. Involucral bracts green or somewhat colored 68. 



68a. Stem more or less prickly DIPSACACEAE, p. 112. 



68b. Stem and leaves not prickly 69. 



69a. Stem square; foliage aromatic when crushed LABIATAE, p. 95. 

 69b. Stem not square; foliage not with the odor of mint 



COMPOSITAE, p. 113. 



70a. The conspicuous portion of the perianth* composed of sep- 

 arate parts 71. 



70b. The conspicuous portion of the perianth* composed of united 

 parts 97. 



Via. 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 P AP AYE RACE AE, 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. 



r /5b. 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. 



* In most flowers the corolla is the conspicuous portion of the perianth, and 

 is composed of united or separate petals, as the case may be. In some flowers 

 tfea corolla is absent, and the calyx is the conspicuous portion. 



