Xll. KEY TO NATURAL ORDERS. 



Stamens alternate with the corolla-lobes; 



Ovary 1-celled, placentae parietal GENTIANACE.E 242 



Ovary 3-celled, placentae axial POLEMONIACE.E 244 



Ovary 1-celled, placentas sac-like lining 



the wall of the ovary HYDBOPHYLLACEJE 251 



B. Leaves alternate; corollas regular. 

 * Stamens opposite the corolla-lobes; ovary 1-celled. 



Styles 5; fruit utricular, 1-seeded PLUMBAGINACE,E 235 



Style 1 ; fruit capsular, oo -seeded PBIMULACE^E 237 



* * Stamens alternate with the corolla-lobes. 



Stamens nearly free from the corolla; anthers 



opening by pores . .' EBICAOE^ 331 



Stamens on the tube of the corolla; 



Flowers spicate; corolla 4-lobed, scarious . . PLANTAGINACE.E 235 



Fruit of 14 seed-like nutlets ASPEBIFOLI.E 257 



Fruit of 2 utricular carpels. ..Dichondra in CONVOLVULACE^: 265 

 Fruit a berry; anthers opening by pores 



Solanum in SOLANACE^: 267 



Fruit capsular; sepals 5; 



Inflorescence unilateral, scorpioid . HYDBOPHYLLACEJE 251 



Leafless yellow-stemmed parasites OUSCUTE^S 266 



Flowers large, axillary; s ads few, large OONVOLVULACE.E 264 

 Flowers small; seeds many, small; 



placentae central SCBOPHULABINE^E 269 



Fruit capsular; calyx 5-toothed or -lobed; 



stigmas, capsule-cells and -valves 3 POLEMONIACE^E 244 



Pistil 2-merous; seeds many, small SOLANACE^E 267 



C. Corollas more or less distinctly bilabiate. 

 * Ovary not lobed; fruits capsular. 



Plants green and leafy ; placentae axial SCBOPHULABINE^E 269 



Plants parasitic, not green; placentae parietal. . OBOBANCHACE.E 284 



* * Ovary 4-lobed, the lobes maturing as nutlets. 



Herbage aromatic; leaves mostly opposite; 

 and flowers densely cymose-congested 

 at the nodes, or few, or solitary; nutlets 

 with basal insertion LABIATE 285 



Not aromatic; flowers simply spicate or capi- 

 tate ; nutlets with lateral insertwn VEBBENACE^ 295 



