T. Holm — Studies in the Cyperacew. 



447 



of which only a few surrounded minute leptomatic-bundles. 

 Similar stereome-bundles imbedded in the pith were, also, 

 observed in F. spadicea, but not in any of the other species, 

 where this tissue is either strictly hypodermal or may be found 

 on the hadrome-side of the innermost mestome-bundles. The 

 largest part of the stem is occupied by a solid pith, mostly con- 

 sisting of polyedric cells, when considered in transverse sec- 

 tions. With the exception of F. spadiceq, of which the pith 

 contained much tannin, this matter was not observed in the 

 pith of any of the other species. 



In regard to the mestome-bundles these are more numerous 

 in the stem than in the leaf; they may form one single and 

 almost concentric band as in F. capillaris (tig. 13), F. Warei, 

 F. eiliatifolia and F. stenophylla, or several as in the other 

 species. They show exactly the same variation as those in the 

 leaves, and the smallest, the orbicular ones, 

 are invariably the most numerous and located 

 near the periphery. Inside of these may be a 

 second band of somewhat larger bundles as in 

 F. autumnalis, F. puberula, F. complanata, 

 F. laxa and F. spadicea, while even a third 

 band is present in F. castanea and F. t/ierma- 

 lis, these two species being the most robust of verse section of the 

 this genus in North America. The minor stem of F. capillaris. 

 structure of the mestome-bundles is the same, x 75, 

 all possessing a parenchyma-, a mestome- and an inner, chloro- 

 phyll-bearing sheath ; besides the relative development of the 

 leptome and hadrome corresponds with what has been said 

 above in the study of the leaf. There are furthermore some 

 leptomatic bundles located in the pith, as mentioned above 

 (fig. 14), but these were only found in one species, F. castanea. 

 These small bundles were surrounded by a few layers of thin- 

 walled stereome, a^so by a sheath, that 

 evidently may be identical with a 

 mestome-sheath ; no inner chlorophyll- 

 bearing sheath was observed here, since 

 these bundles occupied an almost cen- 

 tral position in the pith. 



The peduncle. 



The anatomical structure of the 

 peduncles, which bear the spikes, does Fig.14. a leptome-bundie, 

 not differ in any essential degree from surroundedby stereome from 



Ll , , ,, J T -,-, => ,. the pith of F. castanea : trans- 



tnat or the stem. In J?, castanea, ior ve rse section. x320. 

 instance, the peduncle is slightly com- 

 pressed ; the pith occupies a smaller part of the section and 

 has no bundles neither of pure stereome or with leptome. 



