383 



The flower has five sHghtly hairy perigone-leaves and 

 five lustreless nectary-leaves; the anthers are extrorse or 

 slightly turned sideways; the stamens are few in number, 

 (Fig. 30, D). Ekstam found homogamy and spontaneous self- 

 pollination to occur in Spitzbergen. Lindman also records homo- 

 gamy and figures two kinds of flowers : large ones measuring 

 about 7 mm. in diameter in which the head of carpels is so 

 high that only the lowermost stigmas may be reached by the 

 stamens, and small ones about 4 mm. in diameter in which the 

 stamens stand at the same level as the head of carpels. In 

 Spitzbergen the diameter of the flower is 5 — 8 mm. (Ekstam); 

 in NovaZembla 6 — 10 mm. (Ekstam). The nectaries are simple 

 and pocket-shaped (Fig. 30, B). Lindman and Ekstam did not 

 notice any perfume. 



Flowering takes place in the beginning and middle of 

 summer. In Arctic Norway the plant grows by preference at 

 the snow-line, and the time for the coming out of the leaves 

 may differ greatly even in the case of plants standing close to 

 each other, according as to whether they stand nearer or fur- 

 ther from the snow (Norman). The fruit ripens in August. 



The fruit (Fig. 30, C) is dispersed by the agency of the 

 wind, which may be connected with the fact of the peduncle 

 elongating greatly during fruit-setting; but the dispersal is not 

 very effectual and the plant is often found growing in colonies 

 IEkstam; 1897). 



Stlvén described the germination, which takes place 

 during spring (Cleve). Heterophylly is more decided than in 

 R. nivalis, not until during the second year do the leaves attain 

 the fully-developed form. 



Nathorst has- established a \nr. Langeana which is charac- 

 terized by the leaf-segments of the basal leaves, and sometimes 

 of the lower stem-leaf, being stalked. The middle lobe is 3—4 

 partite, and the lateral lobes are more or less symmetrically 

 2 — 4 partite (Fig. 28, B). The stem-leaves are almost sessile 



25* 



