T. Holm — Studies in the Cyperacece. 445 



American species as only anatomically distinct from other rep- 

 resentatives of Isolepis. Our narrow-leaved species of Fim- 

 bristylis do not show any very important anatomical or 

 morphological characters by which they should be considered 

 as distinct from the others with somewhat broader leaves ; 

 they do not present any such divergencies which induced Rikli 

 to separate his Chlorocyperas and Chlorocharis from' Oyperus 

 and Heleocharis ; besides they lack the very conspicuous char- 

 acter : " bractea infiina erecta, infloresceutiam quasi lateralem 

 saepissime excedens, caulem continuans " as pointed out by 

 Bentham. 



The stem. 



The stem above-ground, which bears the inflorescence at its 

 apex, varies from cylindrical to being almost flattened, but 

 shows, nevertheless, a very uniform structure in our species. 

 The singularly flattened stem of F. autumnalis (fig. 11) and 

 F. complanata corresponds well with the flat leaves, which are 

 turned edgewise in these species. In F. castanea, F. tkermalis, 



Fig. 11. Transverse section of the stem of F. autumnalis. x 60. 



F. spaclicea and F. pubemda the outline is almost cylindrical ; 

 in F laxa it is polyedric ; in F. Warei and F. stenophylla the 

 outline is decangular, while F. capillaris possesses a penta- or 

 hexagonal stem. When compared with the leaf the stem- 

 structure shows many analogies, but the mechanical tissue has 

 here attained a stronger development, the mestome-bundles are 

 arranged in several, more or less concentric, bands and the 

 bark-cells are not arranged radially around the mestome-bundles 

 in all the species. 



While the cuticle of the stem shows the same slight varia- 

 tion as we noticed in the leaves, the epidermis is often more 

 thick-walled and does not develop such dense pubescence as in 



