Species Hybrids in Aquilegia. 



BY 

 EDGAR ANDERSON, 



{Missouri Botanical Garden) 

 AND 



BRENHILDA SCHAFER. 



{John Innes Horticultural Institution.') 

 With four Figures in the Text. 



FROM a morphological point of view most studies of species hybrids 

 have been relatively unproductive. Mendelian analysis, though it 

 has been of great assistance in the investigation of varietal differences, has 

 been possible in only a few instances — East (4), Chittenden (1). Even in 

 these favoured cases it has done little more than demonstrate that certain 

 factors probably behave much the same way in hybrids as they do in the 

 parent species. 



In the following preliminary investigation of species crosses in Aquilegia., 

 an attempt has been made to devise methods of morphological analysis 

 which will on the one hand be useful in codifying the data from crosses 

 between species, and which, on the other hand, will yield objective evidence 

 as to the probable course of evolutionary development. This preliminary 

 account is published to draw the attention of other workers to the problem 

 in the hope that further methods may be developed. 



For a general study of interspecific hybrids the genus Aquilegia is 

 excellent material. Great morphological diversity between species is 

 accompanied by unusual interfertility. The genus numbers roughly 

 eighty to one hundred species, native to Europe, Asia, and North America. 

 They exhibit remarkable morphological and ecological diversity, and can 

 be grouped into at least five different sections. In spite of this diversity, 

 every species cross which has been attempted has produced a first genera- 

 tion hybrid, and all of these have been at least partially fertile. 



Morphologically the genus is particularly interesting by reason of its 

 distinctive petals, which are sometimes interpreted as modified honey 



(Anoals of Botany, Vol. XLV. No. CLXXX, October, 1931.] 



