xiv 



KEY TO THE FAMILIES 



Outer perianth segments green ; inner 



colored. 



Petals ephemeral. 

 Petals withering-persistent. 

 Perianth segments all colored. 

 Flowers irregular or perfect ; stamens 



only three. 



Flowers regular ; stamens six. 

 Flowers not perfect. 

 Flowers perfect. 

 Fruit a capsule. 

 Fruit a berry. 

 Ovary inferior. 

 Aquatic herbs. 



Not aquatics ; flowers regular. 

 Stamens six ; herbs. 

 Stamens six ; vines. 

 Stamens three. 

 Not aquatics ; flowers irregular. 



Petals if present not united. 



Petals none. 



Petals present. 

 Petals present, more or less united. 



II. 



COMMELINACEAK, 55. 

 CONVALLARIACEAE, 61. 



PONTEDERIACEAE, 56. 



MELANTHACEAE, 58. 



LILIACEAE, 58. 

 CONVALLARIACEAE, 61. 



VALLISNERIACEAE, 11. 

 AMARYLLIDACEAE, 62. 



DlOSCOREACEAE, 63. 



IRIDACEAE, 63. 

 ORCHIDACEAE, 64. 



A. 

 B. 

 C. 



A. 



Aquatic herbs. 

 Leaves whorled, dissected. 

 Leaves opposite, entire. 

 Trees or shrubs. 

 Some of the flowers in aments. 

 Leaves odd-pinnate. 

 Leaves simple. 

 Calyx none. 

 Calyx present. 



Pistillate flowers in aments or capi- 

 tate. 



Fruit a nut. 

 Fruit berry-like. 

 Pistillate flowers not in aments and 



not capitate. 

 Flowers not in aments. 

 Leaves pinnate ; plants prickly. 

 Leaves pinnate ; plants not prickly. 

 Stamens usually two. 

 Stamens four-twelve. 

 Leaves not pinnate. 

 Leaves opposite. 



Leaves alternate ; sap not milky. 

 Leaves alternate ; sap milky. 

 Herbs or vines. 

 Ovary inferior. 

 Ovary 1-celled. 

 Ovary 4- eel led. 

 Ovary 6-celled. 



CERATOPHYLLACEAE, 8 

 CALLITRICHACEAE, 126. 



JUGLANDACEAE, 66. 

 SALICACEAE, 67. 



BETULACEAE, 69. 

 MORACEAE, 72. 



FAGACEAE, 70. 

 EUTACEAE, 122. 



OLEACEAE, 148. 

 ACERACEAE, 128. 



ACERACEAE, 128. 

 ULMACEAE, 71. 

 MORACEAE, 72. 



SANTALACEAE, 74. 

 ONAGRACEAE, 138. 

 ARISTOLOCHIACEAE, 75. 



