404 



In each leaf-apex there is an e pit he ma which opens out 

 almost at the margin, upon a slanting, upwardly-directed surface. 

 The tracheids terminate in intercellular spaces and the cells of 

 the epithema have short branches and undulating walls as in 

 the other species iFig. 45, B). 



Fig. 45. Ran. lapponicus. 



A, Surface section of spongy parenchyma (Spitzbergen; ^^^li). B, Longitudinal section of 

 a leaf-apex (Greenland; '^^|{) showing the epithema and some tracheids. 



The leaf- s tal к has three vascular bundles, which are 

 almost like those of the fruit-stalk in structure, but are some- 

 what weaker; the pith and the cortex are lacunose. The epi- 

 dermis contains chlorophyll; the cuticle is furrowed. 



ß. Pallasii Schlecht. 



and 

 R. lapponicus L. ж R. Pallasii Schlecht. 



Lit. Hooker, 1833. Nathorst, 1883, p. 21. Ekstam, 1899, 

 p. 21. Andersson «Sc Hesselman, 1901, pp. 42 — 47 (Figs, of leaf, 

 leaf-anatomy, etc.). 



Alcohol material from Spitzbergen. R. Pallasii: Advent Bay, 

 11.8.1882; the hybrid: Rendalen in Sassenbay, 15.7.1882. 



