100 THE AMERICAN BOTANIST 



I do not know which one of them he would take as the type. 

 It is a composite gens with no clear taxonomic center from 

 which variations diverge. 



Here we have two classes of facts with no way of ex- 

 pressing one of them. If Zca mays were an isolated case, we 

 could treat it as an exception bnt I have before me a list of one 

 or two hundred comparable cases and yet I have made no care- 

 ful search. Botanical literature is full of cultigens, improperly 

 or incompletely co-ordinated into taxonomic treatment. 



The prime deficiency is the fact that many of the good 

 cutigens are unrecognized botanically. In the presumed 

 manual of cultivated plants, how would the author treat the 

 tuberous begonia? Would he enter descriptions of the several 

 indigenous species from which the cultigenous group has come, 

 and stop there? But what then, would the horticulturist do? 

 He would say that Begonia J'citchii, B. Rosacflora, B. Davisii, 

 B. Pea/rcei, and B. Clarkei are not in cutivation as far as he 

 knows and he asks what he shall call the tuberous begonia. He 

 would charge that the tuberous begonia had been left out and 

 he would be correct. 



What are we to do with the cultivated blackberries, ixias, 

 gladiolus, fuchsias, and many of the magnolias, deutzias, 

 spireas, pandanus, roses? What are we to do with the culti- 

 vated canna: what is this plant? Are we merely to pass it by 

 undescribed because it is a complex? To describe the various 

 species of canna is of no consequence to its identification. At 

 present there is no name under which we can describe the com- 

 mon garden canna. The point is, are we to name and describe 

 cultivated plants or are we not? The cultigens are with us and 

 the numbers will increase. No longer can we let them go by 

 default. The plant breeder will bring his new groups; w'ill 

 taxonomy expand itself to receive them or must they forever 

 remain outcasts? Even if we are satisfied to say that the culti- 

 vated blackberries are Rubus Allegheiiiensis,wha.tare we to say 

 when R. Allegheniensis is itself split into a dozen segregates? 



