RANUNCULACEAE 



19 



43. R. lapponicus L. — This species flowers in Spitzbergen from the middle of 

 July to the middle of August, and though ripe fruits have not so far been seen, 

 they were observed to be set in 1897 and 1898. Of the pollen-grains 96 % were 

 normally developed (Andersson and Hesselman, op. cit., pp. 43-7). Ekstam (' Blfiten- 

 biol. Beob. a. Spitzbergen,' p. 227) describes the flowers in the same locality as 

 being yellow, fragrant and protogynous-homogamous, with a diameter of 8-10 or 

 sometimes even 13 mm. Andersson and Hesselman state that the pouch-like 

 nectar-pits are relatively smaller than those of R. Pallasii. 



For Nova Zemlia Ekstam gives the diameter of the protogynous-homogamous 

 flowers as 16 mm. (according to Kjellman, it is 12 mm. in Arctic Siberia). Self- 

 pollination is excluded, for the stigmas project beyond the anthers. 



44. R. Pallasii Schlecht. — This species flowers in Spitzbergen during the end 

 of July and the beginning of August, but perfectly ripe fruits have not so far been 

 observed. Andersson and Hesselman (op. cit, p. 42) state that 96-98% of the 

 pollen-grains are normally developed. According to Ekstam (' Blutenbiol. Beob. 





Fig. 5. Ranunculus glacialis, L. (after Herm. Mailer). A. Petal of a flower with particalarly smaJI 

 perianth ( X 7). B—E. Bases of other petals with variously formed nectaries ( X 7). 



a. Spitzbergen,' pp. 21-2), the white or greenish-white flowers are about 15 mm. 

 in diameter. Nathorst says that their odour is extremely pleasant, resembling that 

 of Platanthera. Andersson and Hesselman state that nectar is secreted in a 

 nectar-pit situated in the upper part of the small claw. Ekstam found the flowers 

 to be protogynous-homogamous. 



Visitors. — Ekstam (op. cit.) noticed one medium-sized and a number of small 

 ' industrious ' Diptera. 



45. R. lapponicus x R. Pallasii. — This hybrid was noticed beneath the parent 

 species in Spitzbergen by Nathorst in 1882, and subsequently in 1898 by Andersson 

 and Hesselman (op. cit., pp. 42-7). Its characters are an approximately equal 

 blend of those of the component species. The flowers are yellowish-white, fragrant, 

 and about xo-13 mm. in diameter. Only 8-12% of the pollen-grains develop 

 normally. The flowers are protogynous-homogamous ; nectar is sparingly secreted 

 by the pouch-shaped nectar-pits. The plant was seen in flower from the end 

 of July on into August, but fruits have so far been observed only in the earlier 

 stages of development. The occurrence of this interesting hybrid shows that the 

 fruits of the mother-plant can actually ripen. 



