z 



394 



G, 0. RosendaliJ. 



find slightly more diversity but no less distinct continuities of development. 

 In this section, three distinct lines are evident. The middle line, re- 

 presented by M. caulescens^ is a direct continuation of M. nuda diffe- 

 ring essentially from the basic type only in having 5 episepalous stamens, 

 and in the slightly larger size of all its parts. The close relationship indi- 

 cated by the floral characters is further strengthened by a very close 

 agreement in the anatomy of the rhizome and scape. In both species a 

 distinct endodermis surrounds the vascular tissue system of the rhizome. 

 The extent and structure of the cortex is almost indentical and the distri- 

 bution of the vascular bundles and the ring of strengthening cells in the 

 scape is the same in both species. These facts are the more noteworthy 

 because all the other species of the genus differ from these two in the 

 absence of an endodermis in the rhizome* 



JUtellast 



Sect. Eumilella 



Fig. 9. 



The two other branches of the section have diverged separately from 

 the basic type. The species of both these branches have the reduced 

 stamen number, but as one series has retained the episepalous stamens 

 and the other the epipetalous ones, it is clear that they trace separately 





