2l8 



Gates. 



mutation from Lainarckiana, to which, however, it bears a peculiar 

 relation (see Gates, 1913 a, p. 28). Ruhricalyx agrees with ruhrinervis 

 morphologically, but differs in pigmentation, showing a greatly in- 

 creased amount of red (anthocyanin) pigment in all parts of the plant 

 but especially in (i) the flower-stalks or hypanthia, (2) the sepals, 

 and (3) on the ventral surface of the midribs of the rosette leaves; 



Fig. 



O. grandiflora grown at St. Louis, Mo. 



(i) and (3) are green in rubrincrvis, red in ruhricalyx. The sepals of ruhri- 

 nervis show a varying amount of red but the median ridge is invariably 

 green, while in ruhricalyx the whole sepal and the median ridge are 

 invariably deep red. (See Gates 1911b, pi. 6.) The contrast in pig- 

 mentation between the two types is therefore very marked and con- 

 stant, and it would be impossible to imagine a more sharp unit-character 



