34i 



origin (Fig, 5, В). The cells of the pith are arranged concen- 

 trically in relation to the vascular bundles which are near 

 them; starch was present (middle of July). 



The above-ground stem. The outer wall of the 

 epidermis is thickened, and the cuticle is distinct; the latter 

 is dentate in transverse section. There are a few, somewhat 

 projecting stomata. Hairs are scanty. Within the epidermis 

 there is a layer of cells which, in the lower part of the stem, 

 are angular and placed closely together; higher up they are 



enti 



Fig. 5. R. glacialis. 



A, Transverse section of rhizome (Tromsö; about ^Vi). e7id, Endodermis; ph. leptome; 

 X, xylem. B, Secondary wood and sieve- tissue with endodermis; from the rhizome 



(about 260/j). 



more rounded in transverse section, and more loosely con- 

 nected to the epidermis and with each other. The cortex 

 consists of lamellae which are one cell-layer thick and sur- 

 round large lacunæ (Fig, 6, B). These plates are often col- 

 lapsed and thereby large^ irregular gaps may occur, which 

 are largest in the lower part of the stem. The epidermis, and 

 especially the outer part of the cortex, contains chlorophyll. 

 The vascular bundles are placed in a circle and number from 

 9 to 11, and are all of about the same size; there are fewer 

 in the peduncle than in the stem. The cells are placed closely 



