(21) 



3. Polemonium. Corolla rotate. Stigmas 

 3. Filaments inserted at equal heights 

 on the tube of the corolla, ascending; 

 anthers incumbent. 



4. Gilia. Corolla rotate funnel-shaped. 

 Stigmas 3. Filaments straight, inserted 

 at equal heights; anthers incumbent. 



5. Collomia. Corolla salver-shaped. Stig- 

 mas 3. Filaments inserted at unequal 

 heights and exserted. 



6. Convolvulus. Corolla funnel-shaped, pli- 



cate, 5-angular. Cells of ovary 2-ovu- 

 late. Calyx marcescent. 



7. Datura. Corolla funnel-shaped, plicate, 

 5-angular. Calyx transversely decidu- 

 ous. 



8. Nicotiana. Corolla funnel-shaped, pli- 

 cate, 5-angular. Calyx persistent. Cells 

 of ovary oo-ovulate. 



9. Rhododendron. Corolla campanulate. 

 Stamens inserted on a disc, not on the 

 corolla. Cells of the anthers opening 

 by pores. Shrubs. 



10. Pentstemon. Corolla irregular, funnel- 

 shaped. Stamens of unequal length, 

 one of them sterile. Capsule 2-celled 

 oo-ovulate. 



