278 T. Holm — Studies in the Cyperaceae. 



to similar investigations. As regards the material which we 

 have examined, the specimens were collected in the following 

 localities: 



G. circinata C. A. Mey., rocky hilltops, 360-375 111 alt., Kadiak ; 

 C. lejocarpa C. A. Me}\, grassy banks, St. George Island, Ber- 

 ing Sea, and marshes at Yes Bay, Alaska ; G. sempervirens 

 Yill., Alps of Switzerland, Tyrol ; G. ferruginea Scop., along 

 streams, 2000 m alt, G. frigida All., 2300 m ait., G jirma Host., 

 2000 m alt., G. hispidula Gaud. 2100 m alt. and G. b'rachystachys 

 Schrank, 1260 m alt., all from the Alps of Switzerland ; G. 

 ablata Bailey, 600™ alt., Vancouver Island ; G. misandra R.Br., 

 St. Mathew Island, Bering Sea ; along mountain streams on 

 Gray's Peak, 4000 m alt., Colorado ; on dry, grassy mountain 

 slopes or swamps, West Greenland ; Rendalen, Spitzbergen ; 

 in swamps on rocks, ISTova Zembla ; Alps of Tyrol at 3000 m 

 alt. 



Tlie root. 



In the species examined we found the roots very strongly 

 built with a more or less thick-walled hypoderm inside the 

 epidermis. The outermost strata of the cortex show a similar 

 thickening and constitute thus a firm sheath around the inner 

 bark, which is thin-walled and usually collapsed throughout to 

 the innermost stratum that rests on endodermis. In G. sem- 

 pervirens the outer six strata of the cortex were especially 

 heavily thickened, also in G. hispidida, in which even the 

 innermost four or five strata exhibited a like thickening, while 

 in C.firma the entire cortical parenchyma was developed as a 

 solid mass of stereids. Endodermis is thick-walled in all the 

 species but not to the same extent ; thus an U-endodermis may 

 be found in G. lejocarpa, G circinata, G. misandra, C. hispi- 

 dida and G. sempervirens, while it appears as a V-endodermis 

 in the remaining species ; the thickening is especially heavy in 

 C.firma and G. sempervirens. The pericambium is most often 

 thin- walled, or in some roots of G. firma, C. frigida and G. 

 sempervirens the cell-walls may be observed as being some- 

 what thickened. It consists of only one stratum, which forms 

 a closed ring in G sempervire?is and sometimes also in 0. 

 Jirma, but is, in the other species, interrupted by the proto- 

 haclrome vessels in a more or less regular manner. We have 

 noticed the following cases : In C. clrcinata, G. lejocarpa, G. 

 ■misandra, G. frigida and C. ablata the pericambium was con- 

 stantly interrupted by all the proto-hadrome vessels, there 

 being mostly four or five pericambium cells between each two 

 of these vessels. In G. hispidula we found in some roots the 

 pericambium interrupted by all the proto-hadrome vessels or 

 by only five out of twenty-five, and these roots were from the 



