T. Holm — Studies in the Cyperacece. 281 



species ; but we fonnd no trace of the inner green sheath, 

 which we remember is known to occur in many genera of the 

 Cyperacem, but not so far known from any species of Car ex. 



There is a central, thin-walled pith in all the species, and this 

 seems to break down, leaving a wide central cavity in all the 

 species examined, with the exception of C. ciroinata. 



The leaf. 



The leaf exhibits a somewhat greater variation than is notice- 

 able in the stem. The narrowest leaf-blade is possessed by C. 

 ciroinata and C. brachystachys, but if we consider the sections 

 taken from the middle of the blade, this is in none of these so 

 narrow that it might be described as semi-cylindrical. The 

 surface of the leaf is very smooth in most of the species, but 

 in C. hispidula the blade is somewhat constricted between the 

 mestome-bundles, besides that the epidermis in this species is 

 very scabrous on either face. In C. brachysiachys the lateral 

 parts of the blade are much thicker than the mediane, and very 

 large prickle-like projections are developed on the upper sur- 

 face on each side of the bulliform-cells. The leaf-surface is 

 thus mostly smooth with no deep furrows, but it is scabrous 

 from prickle-like projections in C. sempervirens, C.ferruginea 

 and C. brachysiachys ; in C. hispidula both surfaces are quite 

 scabrous from the numerous papillae, which also characterized 

 the stem of this species. Bulliform-cells occur on the whole 

 upper face of C. ciroinata and C. lejocarpa, but these cells are 

 in the other species restricted to a single group just above the 

 midrib ; the outer cellwall of epidermis is very thick in some 

 species, for instance, C. hispidida, C. frigida and C. firma, 

 but not so in C. ablata. Some certain variation exists also in 

 the relative length and breadth of the epidermis-cells outside 

 the stereome, and this is especially distinct when we examine 

 the leaf in superficial sections ; we notice, for instance, in C. 

 ferruginea, C. braohystachys and C. misandra that these cells 

 are narrower, but not shorter, than the surrounding epidermis, 

 while in C. sempervirens, C. frigida and C. hispidida they 

 appeared to be much shorter bat not narrower. In C. firma 

 and C. ablata these same cells, covering the stereome, were 

 distinctly both narrower and shorter than the stomatiferous 

 strata. 



In regard to the stomata, these are in the Stenocarpce con- 

 fined to the lower surface of the leaf, and show a very uniform 

 structure ; they are free in all the species, slightly projecting 

 in C. misandra, C. firma and C. ablata, but level with epider- 

 mis in the others ; in C. hispidula, as mentioned under the 



