ARTIFICIAL KEY TO THE NATURAL ORDERS. 309 
171 Ovules erect. The Bindweed Tr., CoNVOLTlTLAOBiB, 493 
Ovules pendulous. The Holly Tr., Aquipolace^, 476 
172 Inflorescence coiled up. The Hydrolea Tr., Hydrophyllace^, 491 
Inflorescence straight 173 
173 Anthers bursting longitudinally. The Greek Valerian Tr., PoLAMONlACEiG, 494 
Anthers bursting transversely. The Diapenaia Tr., Diapenscace^, 495 
174 Stamens two 175 
Stamens four or more 176 
175 ^Estivation of corolla valvate. The Olive Tr., Oleace^, 500 
Estivation of corolla imbricated. The Jasmine Tr., Jasminace^, 499 
176 Inflorescence coiled up. The Waterleaf Tr., Hydrophyllacejc, 491 
Inflorescence straight 177 
177 -Estivation of corolla plaited 178 
Estivation of corolla imbricated ...180 
178 Seeds very few. The Bindweed Tr., Convolvulace^, 493 
Seeds very numerous 179 
179 Leaves three-ribbed. The Gentian Tr., Gentianace^, 492 
Leaves one-ribbed. The Nightshade Tr., Solan AC e^, 496 
180 Anthers adhering to a stigma-like table. The Aaclepias Tr., Asclepiadace^, 498 
Anthers quite free 181 
181 Parasitical leafless plants. The Dodder Tr., Convolvulace^e, 493 
Green leafy terrestrial plants 182 
182 Leaves uniformly three-ribbed. The Gentian Tr., Gentianace^, 492 
Leaves one-ribbed. The Wormseed Tr., Composite, 469 
183 Stigma with an external covering. 
The Brunonia Tr., native of New Holland, allied to Dipsace^, 468 
Stigma in its ordinary naked state..l84 
184 Style one. The Plantain Tr., PlANTAGINAGE.E, 480 
Styles five. The Leadwort Tr,, Plumbaginace^, 481 
185 Ovary four-lobed. The Mint Tr., Labial^e, 489 
Ovary undivided 186 
186 Carpel solitary. 
The Madwort Tr., from Alyssum and kindred genera in Cruciper^, 411 
Carpels two 187 
187 Fruit nut-like 188 
Fruit capsular or succulent 189 
188 Flowers without bracts. The Jffyopornm Tr., allied to Verbenace^, 488 
Flowers with bracts. The Vervain Tr., Verbenace^, 488 
189 Seeds winged. Woody climbers. The Trumpet-Jloioer Tr., Bignoniace^, 485 
Seeds wingless 190 
190 Brown parasites. The Broom Rape Tr., Orobanchace^, 483 
Green leafy plants 191 
191 Fruit two-celled 192 
Fruit with free center placenta. The Butterworl Tr., GENTiBULARiACEiE, 482 
192 Ovary partly inferior. The Gesnera Tr., Gesneriace^, 484 
Ovary quite superior 193 
193 Seeds without appendages. The Fiqwort Tr., Scrophalariaceje, 487 
Seeds with hooked appendages. The Jitsticia Tr., Acanthace^e, 486 
194 Carpel solitary 195 
Carpels more than one,.. .197 
195 Anthers grown together. The Composite Tr., Composite, 469 
Anthers distinct 196 
196 Carpel quite solitary. The Scabious Tr., Dipsace^, 468 
Carpel with two additional abortive ones. The Valerian Tr., Velerianace^, 46? 
'97 Anthers grown together. The Lobelia Tr., Lobeliacbjs, 573 
Anthers distinct 198 
