64 



Pereimails. Flowers not very small. 



Flowers very large. A. succmnbens. 



Flowers medium-sized. Northern plants. 



(A. nitidus.) 27. Hamosi. 



Flowers very small, mostly Mexican. 



29. Micranthi. 



Annuals. 28. Leptocarpi. 



Pods didymous to reniform, cross-ribbed small. 

 Perennials. 



Flowers and fruit in dense heads. 



12. Hypoglottides. 



Flowers and fruit in spikes. 



13. Chaetodontes. 

 Annuals. 30. Didymocarpi. 



