222 T. Holm — Studies in the Cyperacece. 



only occasionally closely packed in these species, and inter- 

 cellular spaces are often not only numerous, but also quite 

 wide ; moreover, lacunes are observable in this tissue and are 

 very broad in all the species, in the " hebetatae," the " cen- 

 trales " and in C. remota (fig. 3). 



The stereome is thickwalled and occurs as hypodermal 

 groups accompanying the mestome-bundles, or separated from 

 the epidermis by the mesophyll, or as isolated groups in the 

 leaf-margins. In the " hebetatce" there is only hypodermal 

 stereome on the leptome-side of the midrib, and also in the 

 margins of the blade, while the smaller mestome-bundles are 

 so deeply imbedded in the mesophyll that the stereome which 

 supports these does not extend to epidermis. In the higher 

 developed types (" centrales," etc.) there is usually hypodermal 

 stereome above and below the larger mestome-bundles, espe- 

 cially well developed in C. Iceviculmis (fig. 4), where it is 

 hypodermal on the lower surface at all the mestome bundles, 

 even at the smallest ones. Considering the mestome bundles, 

 these constitute only a single band in all the species, and are 

 surrounded by a thinwalled parenchyma-sheath and a mestome- 

 sheath, of which the inner wall is moderately thickened ; the 

 leptome and the hadrome exhibit the usual structure, and the 

 bundles occur as oval (in transverse section) or as nearly 

 orbicular. 



The leaves of the Astrostachyce exhibit certain modifica- 

 tions not only in respect to the outline of the leaf, but also in 

 the development of epidermis as bulliform cells or as papillae 

 (C. Iceviculmis) ; moreover, the bifacial leaf of C. remota seems 

 very exceptional, when we compare it with the nearly isolateral 

 leaves of the other species. The structure of 0. exilis, 

 although this seems to represent the highest developed type, of 

 the "hebetatae," at least morphologically, is actually identical 

 with that of the lower forms : C. dioeca and C. gynocrates, 

 while in both C. Davalliana and certain specimens of C. 

 parallela the leaf shows some resemblance to that of the 

 "centrales." A small leaf-surface is characteristic of the u hebe- 

 tates" in contrast to the other types, in spite of the fact that 

 several of these occupy the same kind of soil and live under 

 the same climatological conditions; even in C. gynocrates and 

 C. par 'allela from high northern latitudes the structure of such 

 specimens agree very well with that of others from more 

 southern latitudes or from subalpine regions. 



When we finally compare the "hebetatae" of Astrostachyce 

 with those of some other sections, we do not observe the leaf- 

 blade uniformly narrow in all of these. We have described 

 the relatively broad leaf of C. lejocarpa C. A. Mey. in con- 

 trast to that of G. circinata, both of the Stenocarpce ; further- 



