T. Holm — Studies in the Cyperacece. 427 



approximate, terminalis anclrogyna, basi mascula, reliquse 

 fceminese. The terminal spike in G. holostoma, however, is at 

 least in typical specimens purely staminate, and the species 

 does not seem to be so very closely related to any of these species. 

 In G. alpina the terminal spike is gynsecandrous, and the two 

 or three lateral pistillate spikes are very short and closely 

 sessile forming an almost globular head, while in C. holostoma 

 the pistillate spikes are cylindric, lax-flowered and frequently 

 remote. Figs. 3-6 illustrate the inflorescence of the Greenland 

 plant, and in all of these the staminate spike is very small and 

 partly hidden by the much larger pistillate ones. The number 

 of pistillate spikes varies somewhat, but two seem to be the 

 most common (fig. 3), and the lower one is often remote ; three 

 pistillate spikes (fig. 6) is rather seldom met with, and a single 

 pistillate with or without the terminal staminate may be ob- 

 served in depauperate specimens (fig. 5). The perigynium (fig. 9) 

 is much broader than that of G. alpina and lacks the distinct, 

 emarginate beak. As already suggested by Drejer, G. holostoma 

 is a member of the Melananthce, but we have preferred to 

 place it among the more evolute types, next to G. Raynoldsii 

 Dew., instead of near G. alpina and atrata, on account of the 

 structure of the terminal spike and the perigynium. 



In the Norwegian specimens of G. holostoma we observed 

 exactly the same disposition of the spikes and structure of the 

 perigynium as described above as being characteristic of the 

 Greenland plant. 



So far the species is only known from West Greenland and 

 Finmark, but we should not feel surprised if the geographical 

 range might be extended to the northeastern shores of our 

 continent, for instance along Baffin Bay and Davis Strait. 



In regard to the anatomical structure G. holostoma does not 

 show but a very few points of interest when compared with 

 the other species examined so far ; but taking into considera- 

 tion the fact that the species is very rare and has not so far 

 been studied from this point of view, we have thought that a 

 brief description might be of some interest to students of the 

 genus. The internal structure of the vegetative organs may,, 

 thus, be described as follows : 



The roots. 



All the roots are long, amply ramified and hairy. Inside the 

 thin-walled epidermis is a moderately thickened exodermis of 

 a brownish color. The cortex consists of about ten strata, of 

 which the peripheral three are somewhat thick-walled, but con- 

 tain starch like all the others. The inner layers are collapsed 

 tangentially ; thus this portion of the cortical parenchyma 

 represents a very open tissue. We find in the stele a thick- 



