REVISION OF THE GENUS CALOCHORTUS, 



23 



Rocky Mountains to Nebraska ; and C. albus, which is found for a distance of 

 fully 600 miles in California. 



Those vast regions are as various in soils, climates, and altitudes as any of 

 equal area in the world, yet some kind of Calochortus lives in every portion 

 of it. C. Nuttalli grows in all but desert places, and endures a winter tem- 

 perature as low as 40 degrees below zero, where in the summer the heat is 

 great. C. elegans, C. Lob hi, and C. Leichtlini climb the mountains to an 

 altitude of fully 9,000 feet with often less than three months between two 

 snows ; C. lilacinus delights in wet meadows, where for four or five months of 

 the rainy season it is under water most of the time. C. Purdyi, C. Tolmiei, 

 C. Howelli, and C. Mawea?ius rosens grow in such soils as wheat thrives in, in 

 the Willamette Valley, in Oregon, where summer rains are rather more frequent 

 than in England ; and C. Kennedyi is at home in the desert in a packed 

 gravel, and where for many seasons the rainfall is so slight as to preclude its 

 flowering. C. Vesta grows only in heavy clays, C. aureus in marl, C. venustus 

 robustus in the heavy packed soils around wet swales, and C. striatus in saline 

 meadows. 



It is a peculiarity of Calochorti, as well as many other Pacific Coast lilia- 

 ceous plants, that in a given section of country there is, as a rule, little variation 

 from a well-marked type. A short distance away there is a type slightly but 

 constantly different, and by slight steps the variation increases, until at points 

 remote from each other differences are to be noted which might well merit 

 the distinction of being called species, did not intervening localities offer such 

 a perfect chain of intermediate forms as to make segregation impracticable. 



I have no doubt that these local sub-species are adaptations to the condi- 

 tions, and the genus as a whole is one of the finest examples to be found in 

 nature of an evolution accomplished and rapidly going on. 



These local sub-species may be found over an area of a few miles square, or 

 they may extend for hundreds of miles where the same climate and soil con- 

 tinue for long distances. East of the Sierra Nevada mountains and the Cas- 

 cades, their northern continuation, we find that C. Nuttalli, C. macrocai-pus, 

 and C. nitidus are found for hundreds of miles without any material variation ; 

 west of the Sierras, in California, we have in the foothills, at about a uniform 

 elevation, in the same soil and accompanying the same shrubs and trees, C. albus, 

 scarcely varying at all for 300 miles, while in the coast range, with its endless 

 climates and soils, changes come frequently in the local types. 



Hybrids are not uncommon. I have seen hybrids between C. albus and 

 C. Benthami, C. pulchellus, and C. Mawea7tus, and between the strains of C. 

 luteus, but I have still to see a fertile hybrid between the first two crosses men- 

 tioned. While I have observed such hybrids as I have spoken of, I have, after 

 diligent search, failed to find the least evidence that some strains, which to a 



