T. Holm — Studies in the Cyperacem. 



221 



but not shorter, while in C. echinata and O. elongata the same 

 cells are not only much narrower, but also shorter than the 

 others. The stomata are restricted to the lower surface of the 

 leaf-blade outside the mesophyll ; they are free in all species, 

 even in C. Iceviculmis with its numerous papillge, and the 

 guard-cells are level epidermis in most of the species, with the 

 exception of C. parallela, C. sterilis, C. elongata and C. Icevi- 

 culmis, in which they are slightly projecting. 



M. 



Fig. 3. Carex remoia L. ; fig. 4, C. Iceviculmis Meinshaus. ; fig. 5, G. echinata 

 Murr. Transverse sections of leaves; M.= midrib; E.= epidermis of upper 

 face, developed in bulliform cells above the midrib ; mesophyll painted black. 

 xl20. 



The mesophyll consists mostly of a homogeneous tissue of 

 short palisades vertical on the leaf-blade or radiating towards 

 the center of the mestome-bundles as we observed in C. 

 Davalliana y in G. echinata, C. sterilis and C. Imvioulmis the 

 palisades are very short and often too irregular in shape to be 

 called u palisades." In G. remota the mesophyll is differen- 

 tiated into a ventral palisade- and dorsal pneumatic-tissue, this 

 species being, thus, the only one of the section that possesses 

 a typical bifacial leaf-blade. The cells of the mesophyll are 



