BoT.— Vol. II.] PURDY—CALOCHORTUS. 109 



the plants found for hundreds of miles along the Sierra; 

 another strain is found in the same species occurring in the 

 Coast Range and over an equal area. In some of the more 

 variable species there are several strains. 



In many of the Calochorti the gradations from one species 

 to another are so slight that it is impossible to separate them. 

 The extreme types on which the species are founded are 

 easily distinguishable, but a perfect chain of variations links 

 them closely together. There is no doubt that C. weedii, 

 C. phinimerce^ and C . obis-po'ensis are variations of a greater 

 species. 



While, as before stated, it is the rule that a given locality 

 produces specimens conforming closely to a type, yet this 

 is not always the case. In some localities the variations are 

 bewilderingly numerous. I have seen places where hun- 

 dreds of flowers of C . vemistus could have been selected, 

 each differing in color and markings from the rest. Why 

 a species that remains so true to a type in some localities 

 should vary so remarkably in others is a subject that will 

 not be discussed at present. Hybridization will account for 

 it in some instances, while in others it is hardly a tenable 

 hypothesis. 



I cannot say that I attribute any material share in the 

 origin of the many strains or varieties to hybridization, 

 although among the Calochorti it is not infrequent. Such 

 crosses as C. albus and C. benthami, C . maweanus and C . 

 piilchellus are frequently met with, but I have never yet seen 

 one that was fertile. Again, varieties of a species, e. g., 

 C. luteus var. oculatus and C. luteus var. citrinus, readily 

 cross and produce fertile hybrids. Over a small area in- 

 numerable cross-breeds may be found, but a few miles away 

 the two varieties will be found separate and varying as little 

 as in any locality. Then again, hybridization often will not 

 take place between two apparently very closely related 

 species. I have often seen C. vesta in flower surrounded 

 by large numbers of C, luteus var. oculatus or var. citrinus, 

 but not a plant could be found that in any way indicated 

 hybridization; while last summer, in the Sierra Nevada, I 



