T. Holm —Studies in the CyperacecB. 59 



larojer mestome-bundles aslijpodermal groups on the leptome- 

 side of these, while it is much less developed on the hadrome- 

 side; the smaller mestome-bundles have mostly only a few 

 stereome-cells on the leptome-side ; an isolated group of ster- 

 eome is located in the leaf-margin. In regard to the mestome- 

 bundles, these are all arranged in one band, large and oval in 

 alternation with small, almost orbicular; they are surrounded 

 by a thin-walled, green parenchyma-sheath, besides by a mes- 

 tome-sheath of which only the inner cell-walls are thickened ; 

 no thick-walled mestome-parenchyma was observed. 



Carex Breweri exhibits a leaf-structure, which corresponds 

 in most respects with that of the two similarly narrow-leaved 

 Carices from the dry rocks in the alpine and arctic regions: C, 

 nardina Fr. and C. elynoides nob. besides with that of JElyna 

 Bellardi Koch. When compared with the narrow-leaved spe- 

 cies, which occur in wet places, for instance : C. i^'^dicavis L., 

 gynocrates Womskj., dioica L., paralela Lsest. and exilis Dew., 

 we noticed a prominent difference in the leaf-structure, depend- 

 ing upon the non-differentiation of the large colorless tissue, 

 besides that the cross-section is more or less triangular in 

 contrast to the almost hemicylindric outline, observed in C. 

 Breiceri. 



In regard to the culm, this is cylindric, furrowed and gla- 

 brous; the internal structure corresponds with that of the leaf 

 and the central portion is occupied by a large, thin-walled pith, 

 separated from the narrow layers of mesophj^l by wide lacunes. 

 There is, thus, a very important difference from a morphologi- 

 cal and anatomical viewpoint between C. F'7'aseri 2ind O. Breweri, 

 and no evidence of affinity, close enough to consider them as 

 members of the same section is, so far, apparent. 



The third species, which bj^ Professor Bailey is enumerated 

 as one of his PhysocephcdcB, is C. Engelrnannii Bail., very 

 briefly described in his preliminary synopsis (1. c). This inter- 

 esting species was first collected by Dr. Geo. Engelmann, in 

 the upper Clear Creek region of Colorado, at an elevation of 

 12,000 ft., and it appears to be very rare, as it has only been 

 found once since by Dr. P. A. Eydberg, who rediscovered it on 

 the high mountains near Silverplume, Colorado, in the same 

 region from where it was first recorded. Since the species is, 

 thus, very little known, we have thought it worth while to 

 present an illustration of it (fig. 1), showing one of the speci- 

 mens, which Engelmann collected, and which was kindly loaned 

 to the writer by Professor William Trelease. Furthermore we 

 append a diagnosis, since, as stated above, the plant has hitherto 

 only been briefly described, and since some of its more salient 

 characters have been overlooked. 



