42 T. Holm — Studies in the Cyperacem. 



shows a distinctly thickened outer zone in the two other species. 

 The inner cortex shows the usual tangential collapsing. Endo- 

 dermis is exceedingly thick-walled in G. Willdenowii and G. 

 Backii, but not so in the third species. The pericambium is 

 more or less thick- walled in all three species and it is, also, 

 interrupted by all the proto-hadrome vessels. In C. Backii 

 we noticed that the average number of pericambium-cells 

 between each two proto-hadrome vessels was only two or three, 

 while there were four in the others. The conjunctive tissue 

 was quite thick-walled in C. Steudelii and G. Willdenowii, but 

 much less so in G. Backii. The root-structure is thus very 

 uniform in these species, and agrees very much with that of 

 G. ozdipostyla, except that the pericambium is much more 

 thick-walled in this species, besides that there are here mostly 

 five pericambium-cells between each two proto-hadrome vessels. 

 Very different is the structure exhibited by G. Geyeri and G. 

 multicaulis. The cortex in the former consists exclusively of 

 very thick-walled parenchyma, which is more or less collapsed 

 though without leaving any lacunes ; in the other species, G. 

 multicaulis, it is only the outermost five or six strata that are 

 thick-walled, while the inner are quite thin-walled, but not col- 

 lapsed, although the root was apparently of the same age as 

 the others. The endodermis is exceedingly thickened, espe- 

 cially on the inner walls, and very porose. The pericambium, 

 which is not very thick-walled, is in both species only inter- 

 rupted by some of the proto-hadrome vessels, but in different 

 ways : in G. multicaulis every other proto-hadrome vessel 

 bordered on endodermis, in almost regular alternation, while in 

 C. Geyeri there was only one vessel out of thirteen which did 

 not border on the endodermis ; in some other specimens we 

 noticed that fourteen of twenty-three proto-hadrome vessels 

 were situated inside the pericambium. 



The rhizome 



is cespitose and very short in our species with the exception of 

 G. Geyeri, in which there is a creeping rhizome, but of very 

 short internodes and sympodial as in most of the other Garices. 

 The cortical parenchyma is quite broad and somewhat thick- 

 ened all through in C. Steudelii, but not so in C. Willdenowii. 

 The endodermis is thickened like an O — endodermis in both 

 species. The stereome is only to be observed as accompany- 

 ing the mestome-bundles, which it surrounds completely, while 

 it does not occur in the cortex as independent strata or groups. 

 The mestome-bundles are irregularly scattered in several, about 

 four bands, and are nearly all perihadromatic ; there is, further- 

 more, a solid, central pith of slightly thickened cells. In C. 



