36 T. Holm — Studies hi the Cyperacece. 



Carex Bossii Boott. 



It is strange to see liow often vegetative characters are 

 overlooked by systematic writers. The structure of the 

 rhizome for instance is very seldom studied, and by looking at 

 the plant descriptions in the last edition of Gray's manual, in 

 the Synoptical Flora and other more recently published works, 

 it is too evident that this part of the plant might have been 

 considered and studied much more carefully. Even in such 

 inconspicuous and uniform looking plants as our Carices does 

 the structure of tlie rhizome, of the leaves and the culms afford 

 good characters for distinguishing closely allied species, and 

 sometimes easier than the structure of the utriclC; or the scales. 

 And the fact that the vegetative characters have been left out 

 altogether in descriptive works upon Carex has resulted in 

 mistakes, that could easily have been avoided. 



One writer^ has for instance stated that the European 

 Carex pilulifera is identical with the North American C. 

 coinmimis (C. varia of many authors), by presenting an 

 elaborate table of measurements of spikes, of the distance 

 between these, of the length of the utricle, of the beak, etc., etc., 

 but overlooking the fact that C pilulifera' is phyllo-, C. com- 

 munis aphyllo-podic, not speaking of the extremely different 

 habit possessed by these species, when studied " in the field." 

 A similar disposal has been madef of Horneman's C deflexa 

 and Boott's C. JRossii^ in this way that C. deflexa is enumerated 

 as the type of a species with four varieties, Deanei^ media, 

 JRossii and Boottii. Of these C. Bossii is the only one which 

 occurs in Colorado, and a study of this plant has led us to the 

 belief that it is specifically distinct from the Greenland C. 

 deflexa, as Boott himself considered it to be. The latter species 

 we have had the opportunity to observe in a living state in 

 Greenland, and it never appeared to us, when we found the 

 former, C. Bossii, in Colorado, that they should represent the 

 same species. There is, among other characters, exactly the 

 same and very conspicuous distinction noticeable in C. Bossii, 

 when compared with C. deflexa, as we have described above 

 between C.jpilidifera and C. communis: C. Bossii is aphyllo-, 

 C. deflexa phyllo-podic. 



To fully emphasize the importance of this character, it is, of 

 course, necessary to study a number of specimens collected at 

 different seasons, and to compare the different shoots, floral 

 and vegetative, and their leaves. But besides this distinction 

 derived from the shoots, the structure of the rhizome itself 

 deserves, also, some attention. Thus is the rhizome of G. 



*M. L. Fernald in Contrib. Gray Herb., vol. xxii, p. 503, 1902. 

 fL. H. Bailey in Mem. Torrey Bot. Club., vol. i, p. 43, 1889. 



