T. Holm — Studies in the Gyperacece. 223 



more in G. pulicaris the leaf is very narrow as in G. pyrenaica, 

 but broad in G. nigricans, their nearest ally ; a relatively 

 broad blade is noticeable in the "hebetatse" of Sphwridio- 

 phorce, e. g., G. soirpoidea and G oreocharis, and in Lampro- 

 chlcence : G. rupestris and G. obtusata. 



Utriculus. 



If it were not that this organ possesses such excellent 

 morphological characters, by which our species of .Astrostachyw 

 may be readily distinguished from each other, one would natu- 

 rally suppose that the number of species were much smaller 

 by examining the anatomical structure. The fact is, that 

 when we examine the structure of utriculus, we do not find 

 any points of importance by which these species may be dis- 

 tinguished anatomically. The differences are so slight and 

 seem merely to depend upon a relative broader or narrower 

 mesophyll and a larger- or smaller number of isolated stereome- 

 bundles, that none of these may be considered as being neither 

 constant or of sufficient importance to be used as anatomical 

 characters. Common to all is the broad mesophyll at the base 

 of utriculus, and the presence of only two mestome-bundles ; 

 furthermore, the stereome is equally well developed in these 

 species, not only as accompanying the mestome-bundles, but 

 also by occurring as isolated, hypodermal groups between these. 

 The number of these isolated stereome-bundles varies from 15 

 to 36, the strongest mechanical structure being possessed by 

 G. elongata, G. dioeca and G. gynocrates. The outer epidermis 

 is thickwalled in most of the species excepting G. remota and 

 G. Iceviculmis. 



When we finally compare the morphological and anatomical 

 characters with each other, it seems as if our species may be 

 naturally classified as representing a section of Vignece. The 

 transition from the " hebetatse " to the " centrales " seems very 

 gradual and as we have shown in the preceding, none of these 

 species possess characters that stand as isolated among the 

 others, neither in morphological or anatomical respects. If our 

 disposition of these species, classified as " Astrostachyce" may 

 prove to be correct or at least quite natural, our observations 

 have simply confirmed a suggestion, already proposed by both 

 Tuckermann and Boott, whose remarks upon the affinities 

 have been presented in the introduction to this paper. 



Brookland, D. 0., July, 1900. 



Am. Jour. Sci— Fourth Series, Yol. XI, No. 63.— March, 1901. 

 15 



