20 



ANGIOSPERMAE—DICOTYLEDONES 



46. R. sulphiireus Sol. — According to Ekstam, the diameter of the flowers is 

 16 mm. ; in Arctic Siberia (Kjellman) and on Nova Zemlia it is distinctly greater. 

 In Spitzbergen this observer (op. cit., p. 23) found the flowers to be protogynous- 

 homogamous, and faintly fragrant. In expanded blossoms the gynoecium projects 

 so far beyond the stamens that autogamy is prevented. Andersson and Hesselman 

 (op. cit., p. 49) state that this species flowers in Spitzbergen from the end of June 

 until August, the fruits being ripe at the end of the latter month — or much earlier 

 near the deep fjords. 



Visitors. — Ekstam observed seven distinct cases in Spitzbergen where the flowers 

 were visited by numerous Diptera, and he also noticed these insects elsewhere. 



47. R. pyrenaeus L. (Ricca, ' Oss. suUa fecondaz. incroc. d. veget. alp, 

 e subalp.,' p. 3 ; Herm. Miiller, 'Alpenblumen,' pp. 132-3 ; MacLeod, ' Pyreneenbl.,' 

 p. 114.) — In this species the nectaries are also very variable, as the accompanying figure 

 shows (Fig. 6). According to Ricca, cross-pollination is at first favoured by feebly 



Fig. 6, Rannnctthis pynnaeuSy L. (after Herm. Miiller). 1-12. Various forms of nectary. 

 h, nectar. 13. Transition from petal to stamen. 



marked protogyny. Subsequently — according to Miiller — cross- and self-pollination 

 are equally possible as the result of insect-visits. During this stage, automatic self- 

 pollination by means of the inner stamens can easily take place. 



Visitors. — Hermann Miiller observed— in the Alps — 2 beetles, 9 flies, one 

 Ichneumon, and one micro-Lepidopterid. MacLeod observed — in the Pyrenees — 

 2 flies. 



48. R. alpestris L. (including R. Traunfellneri Hoppi). (Herm. MuUer, 

 'Alpenblumen,' pp. 130-1; Kerner, 'Nat. Hist. PI.,' Eng. Ed. i, II.) — According 

 to Miiller, cross-pollination is at first favoured in the homogamous or slightly proto- 

 gynous flowers, but afterwards self-pollination is possible. The hermaphrodite 

 flowers — according to Kerner — occur in two forms, as in Anemone alpina. Kerner 

 also observed pseudo-hermaphrodite pollen flowers. 



Visitors. — Hermann Miiller observed 1 9 flies, one beetle, one humble-bee, 

 and 2 Lepidoptera. 



