T. Holm — Studies in the Cyperacew. 219 



orae, and, with the exception of 0. Iceviculmis (fig. 1), this 

 is here separated from the epidermis by strata of cortical 

 parenchyma on the leptome side. It may be said about the 

 stereome in these species, that it is generally well developed 

 and seems to be especially thickwalled in C. Iceviculmis and 

 C. remota. In regard to the mestome-bundles, these are 

 arranged in one peripheral band and represent larger, in trans- 

 verse section oval, and smaller, which are nearly orbicular in 

 outline ; the parenchyma-sheath is thin walled and the mestome- 



FiG. 1. Transverse section of the stem of Carex Iceviculmis Meinshaus. 

 The cortex is painted black in the figure, lacunes are to be seen between the 

 mestome-bundles, and the central portion of the pith is broken down into a wide 

 cavity, x 75. 



sheath shows a distinct thickening of the inner cell-wall in all 

 the species, and to the same extent. The mestome-bundles are 

 thus of the same development as is usually observed in the 

 genus, and we might state besides, that we found no trace of 

 the inner chlorophyll-bearing sheath, which Haberlandt and 

 Rikli detected in some of the other genera of the order. 



The leaf. 



This organ exhibits a much greater variation in these species 

 than observed in the root, the rhizome and the stem. It is 

 mostly hemicylindric in the "hebetatse," at least in C. dioeca, 

 0. gynocrates (fig. 2) and 0. exilis, where this leaf-shape is 

 characteristic of both the male and female plant, besides in 

 monoecious specimens of O. gynocrates ; in C. parallela, on 

 the other hand, we noticed the leaf to be broader in the male 

 than in the female plant, and in O. Davallia?ia the leaf is still 

 broader and almost carinate. In the central forms as well as 



