Primulaceae. 187 



The epidermal cells of both surfaces have their lateral walls 

 strengthened by thickened bands at right angles to the 

 surface; these originate fairly regularly from the convex side 

 of the wall-foldings (fig. 11, a and b). Numerous cells with 

 brown contents are found in the epidermis. Børgesen states 

 that the number of stomates is somewhat larger on the upper 

 than on the lower surface, but the opposite is the case in 

 the leaves examined by me, where the larger number of 

 stomates is on the lower surface. The stomates both on 

 the upper and lower surfaces of the leaf, are most numerous 

 towards the apex and near the margin. Glandular hairs occur 

 evenly distributed, though rather scantily, over the whole 

 surface of the leaf. As was the case with the two pre- 

 ceding species, the mesophyll is loose and little differentiated 

 in structure (fig. 11, c). The uppermost layer consists of 

 short, thick and often almost isodiametric cells ; in the lowest 

 layer the elements of the mesophyll become somewhat 

 ramose and more horizontally elongated. Chlorophyll granules 

 are plentiful throughout the mesophyll, and also in the 

 epidermis of the lower surface, but they are few or entirely 

 absent in that of the upper surface. Hydathodes are present 

 on the margin of the leaf. 



The floral parts are anatomically very similar to the corres- 

 ponding parts of Pr. sibirica. The hair -covering of the 

 calyx lobes consists principally of the type of glandular 

 hairs illustrated in fig. 5, e. 



Primula farinosa L., var. groenlandica (Warming) Pax. 



Lit.: Lange, 1880, p. 70 (Pr. stricto); 1887, p. 260 

 (Pr. stricta var. groenlandica, Warming). E. Warming, 1886 a, 

 p. 21 etc. (Pr. stricta var. groenland.). Kosenvinge, 1892, p. 683 

 (Pr. farin. var. mistassinica (Mich.) Pax). Abromeit, 1899, pp. 

 37 — 40 (Pr. farin. var. mistassin.) . Pax and Knuth, 1905, p. 84. 



