58 T. Holm — Studies in the Cyperacece. 



cells, which is the more peculiar when we consider the unusual 

 breadth of the leaf-blade in contrast to other broad-leaved 

 species ; furthermore that the stem above ground, the culm, 

 is flat and hollow. These are features of such importance that 

 the species maj be well separated from all the other Carices as 

 occupying a section of its own among the Carices gemcincB. 

 Its snow-white inflorescence and broad, deep-green leaf gives to 

 the plant a very singular aspect, yet tlie minor structure of the 

 staminate and pistillate flowers is that of a true Carex. 



The utricle is small for the size of the plant and the texture 

 is very thin on account of the very delicate structure of the 

 epidermis and the poorly developed mesophyll, besides that the 

 very weakly developed mestome-bundles are only supported by 

 a few strata of thin- walled stereome. ]^one of these characters 

 are mentioned by Professor Bailey, who established the section 

 Physocejyhalce. * 



In passing to describe the other species, formerl}^ supposed 

 to represent allies, C. Breweri Boott also shows, to some 

 extent, a peculiar habit, though only in respect to the structure 

 of utriculus. Boottf describes the utricle in this way : " peri- 

 gyniis ovalibus amplis inflatis tenuissimis, leviter nervatis glab- 

 ris fulvis rostellatis, ore albido oblique secto," and he com- 

 pares the species, as far as concerns the large, inflated perigy- 

 nium, with C. Mertensii ^wd C. Baiiksii ; the plant, however, 

 shows no affinit}^ to any of these two species. The utricle of 

 C. Brevjeri is, thus, very large and inflated, altogether very 

 unlike that of C. Fraseri^ and we might state furthermore 

 that the anatomical structure is, also, very different. Only the 

 outer epidermis persists ; it is very thin-walled and constitutes 

 the only tissue between the two mestome-bundles, which are 

 surrounded by a few laj^ers of mesophyll, while no stereome 

 was observed in our material. The leaves of C. Breweri are 

 very narrow, almost flliform, with a shallow groove on the 

 upper surface (fig. 5), and glabrous with exception of the mar- 

 gins, where short, prickle-like projections are developed in a 

 few rows. The epidermis shows the outer cell-walls very much 

 thickened, and the stomata, which are here restricted to the 

 dorsal face of the blade, are slightly sunk below the outer cell- 

 wall of epidermis ; no buUiform cells are developed. The 

 mesophyll consists of about six layers of palisades, arranged 

 vertically on the leaf-face, partly surrounding the mestome- 

 bundles and located close to the dorsal face of the blade. But 

 the greater portion of the leaf is occupied by a colorless tissue, 

 which soon breaks down and forms lacunes of quite considera- 

 ble width. The stereome is thick-walled and accompanies the 



* A preliminary synopsis of North American Carices, 1886, p. 132. 

 \ 111. genus Carex, vol. iv, p. 142. 



