ARTIFICIAL KEY TO THE NATURAL ORDERS. 
307 
120 Flowers unisexual; that is, having stamens in one flower, and pistils in 
another 121 
Flowers bisexual; that is, having stamens and pistils united in the same 
flower 123 
121 Carpels solitary. 
Carpels more than one 
122 Flowers in catkins. 
Flowers not in catkins. 
123 Sepals two. 
Sepals more than two 
.124 
The Nettle Tr., Urticace^, 628 
The Birch Tr., Betulacb^, 524 
The Euphorbia Tr., Euphoubiace:^, 519 
The Purslane Tr., Portulacacb^, 419 
124 Carpels solitary, or quite separate 125 
Carpels more than one, consolidated 128 
125 Fruit a legume. 
Fruit not a legume 126 
126 Calyx membranous. 
Calyx firm and herbaceous 127 
The Pea Tr., Leguminos^, 444 
The Knotgrass Tr., Polygonace^, 506 
127 One style to each ovary. 
Three styles to each ovary. 
128 Placentas parietal. 
Placentas in the axis 129 
129 Calyx membranous and ragged. 
Calyx firm and equally lobed 130 
130 Calyx valvate 131 
Calyx imbricated. 
131 Stamens monadelphous. 
Stamens distinct 132 
132 Stamens 4-5, opposite the petals. 
Stamens 8-10. 
The Rose Tr., Rosacea, 445 
The Buchwheat Tr., Polygonace^, 506 
The Passion Flower Tr., PASSlFLORAOEiE, 456 
The Elm Tr., ULMACEiE, 513 
The Geranium Tr., Geraniace^, 429 
The Sterculia Tr., allied to Malvace^, 421 
The Buckthorn Tr., Rhamnace^, 441 
The Linden Tr., Tiliace^, 422 
133 Flowers bisexual ; that is, having both stamens and pistils in the same 
flower 135 
Flowers unisexual; that is, having stamens and pistils in separate flowers 155 
134 Sepals two. 
Sepals more than two 135 
The Purslane Tr., Portulacace^, 419 
135 Carpels several, consolidated 136 
Carpels solitary, or if several quite distinct 144 
136 Placentas parietal. 
Placentas in the axis 137 
137 Number of ovules very small 138 
Number of ovules very great 140 
138 Leaves dotted. 
Leaves not dotted 139 
139 Embryo curved. 
Embryo straight. 
140 Carpels divaricating at point. 
Carpels consolidated at the point. ..141 
141 Stamens perigynous 142 
Stamens hypogynous 143 
142 Fruit one-celled. 
Fruit with several cells. 
1*3 Calyx tubular. 
Ciiljx of distinct sepals. 
The Popjiy Tr., Papaveracejs, 409 
The Rue Tr., Rutace^, 433 
The Poke Weed Tr., PhytolACCACE^, 502 
The Celastrus Tr., Celastrace^, 440 
The Saxifrage Tr., SaxifrAGACE^, 460 
The Primrose Tr., Primulace.*:, 479 
The Lithruni Tr., Lythrace^e, 449 
The Pink Tr., CAUYOPHYLLACEiB, 418 
The Chickweed 7V., Puimulace^iE, 479 
