i 02 



tlie rhizomes of llic sjjecies willi erect stems: the hiiridles 

 anastomose aiul lorm a more or less complete riiii; aroiiiid Ihe 

 pith; llie latter and tlie cortex are less lacunose; the cells of 

 the latter are somewhat langenlially elongated and there are 

 more cortical layers than in the internodes. Roots arise from 

 the nodes. 



The flower- s talk, especially towards the time for the 

 ripening of the frnit, is rather rich in stereom (Fig. 43). It is 

 somewhat polygonal in transverse section. The cuticle is deci- 

 dedly striped, and the stomata project above the surface. The 

 cortex has large intercellular spaces. Each bundle (3—6) is 



surrounded by a sheath of stereom; 

 there is strong fibrous tissue out- 

 side the leptome. Between the wood 

 and the cambium there is a several- 

 layered mass of wood-parenchyma 

 with highly thickened walls, and 

 between the vessels and the endo- 

 dermis there is some non-lignified 



parenchyma. The interfascicular, 

 Fig. 43. R. lapponicus. ,. .„ , , . - « , 



Portion^of transverse section of pe- hgnihed parcnchyma IS 0—6 layers 



duncle (Spitzbergen ;-.Vi).ep, Epidermis: ^|^j^j^ ^^^^ ^g ^jj|jg ^^^ rather higllly 

 c, cortex; t, intercellular space; /;, bast; 



ph, leptome; x, xylem; p, non-lignified thickCUed. The pith iu thC peduucle 

 parenchyma ; vp, lignified parenchyma. 



is found partly broken down ; its 

 cells were slightly lignified. — The epidermal' cells contain 

 chlorophyll. 



The leaf. The epidermal cells as usual, have only slightly 

 thickened outer walls. The cells contain chlorophyll. Seen 

 with the naked eye the leaf shows brown spots upon both sur- 

 faces: many of the cells of the epidermis being filled with brown 

 juice, probably tannin (it did not, however, give the reaction 

 with the iron-salts). The walls of the upper epidermis are 

 slightly undulating and stomata are almost entirely absent; the 

 walls of the lower epidermal cells are highly undulating (Fig. 



