

Studies in Sisyrinchium — IX : The Species of Texas and the Southwest 



By Eugene P. Bicknell 



The present paper has to do primarily with the blue-eyed 

 grasses of Texas but, for convenience, it is made to embrace as 

 well the species known from the adjoining states and territories in- 

 eluding also Arizona. In all some twenty-five species are recog- 

 nized from this general southwestern region seventeen of which are 



proposed as new. It may safely be said, however, that this 

 enumeration is far from complete, for the lack of any specimens 

 from many sections of the region, as well as the evidence afforded 

 by fragmentary material here passed over, allows little doubt that 

 the number of species actually occurring is materially greater than 

 yet appears. Very few specimens have come to hand from Arizona 

 and New Mexico, and still fewer from the extreme western and 

 southern boundaries of Texas. From the latter state seventeen 

 species can be recorded, and there is little doubt that at least three 

 other known species occur, these being S. de mis sum Greene, to be 

 expected in the extreme northwestern part of the state, S. albidum 

 Raf, in the northeastern part, and S. campestre in the northwestern 

 and northern section. 



The Texan species taken as a group present several noteworthy 

 features of botanico-geographical interest. Not only do none ot 

 the distinctly Texan species, as far as appears, extend for any dis- 

 tance beyond the borders of the state to the north or east, but, 

 conversely, very few of the more northern or eastern forms cross 

 the Texan border, and not one of them for any great distance. 



Between the Texan and Mexican species a similar mutual ex- 

 clusion appears to obtain, and in some considerable collections of 

 Mexican species which have passed under notice not a single 

 species known from Texas has been encountered. It is scarcely 

 to be expected, however, that there is not some interchange o\ 



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species along the border. It may also be noted that no species 

 occurring in Texas appears to be generally distributed throughout 

 the state. 



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