Xll. KEY TO NATUEAL OEDERS. 



Stamens alternate with the corolla-lobes; 



Ovary 1-oelled, placentae parietal Gbntianacbjs 242 



Ovary 3-celled, placentae axial Polbmoniacb* 244 



Ovary 1-celled, placentae sac-like lining 



the wall of the ovary HydrophyllaoEjE 251 



B. Leaves alternate; corollas regular. 

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



Styles 5; fruit utricular, 1-seeded PiiUMBaginace« 235 



Style 1; fruit capsular, co -seeded Primui,acb.ze 237 



* * Stamens alternate with the corolla-lobes. 



Stamens nearly free from the corolla; anthers 



opening by pores Ericaoe.e 331 



Stamens on the tube of the corolla; 



Flowers spicate; corolla 4-lobed, scarious. .Plantaginace^; 235 



Fruit of 1 — 4 seed-like nutlets Asperipoli^; 257 



Fruit of 2 utricular carpels. ..Dichondra in Convolvulace/E 265 

 Fruit a berry; anthers opening by pores 



Solanum in Solanaoe^; 267 



Fruit capsular; sepals 5; 



Inflorescence unilateral, scorpioid Hydrophymgace.e 251 



Leafless yellow-stemmed parasites Ouscute^; 266 



Flowers large, axillary; seeds few, large Oonvolvulace.*: 264 

 Flowers small; seeds many, small; 



placentae central Sorophulabine^e 269 



Fruit capsular; calyx 5-toothed or -lobed; 



stigmas, capsule-cells and -valves 3 Polemoniaceve 244 



Pistil 2-merous; seeds many, small Solan ace.es 267 



C. Corollas more or less distinctly bilabiate. 



* Ovary not lobed; fruits capsular. 



Plants green and leafy; placentae axial Scbophularine^; .269 



Plants parasitic, not green; placentae parietal. . Orobanchace*; 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 insertion Verbenace^i 295 



