RANUNCULACEAE 31 



Herm. Miiller noticed in the Alps : 3 beetles, 20 flies, 7 Hymenoptera, and 

 19 Lepidoptera. 



69. R. illyricus L. 



Visitors. Schletterer observed the following Apidae. 1. Halictus calceatus 

 Scop.; and 2. H. fasciatellus Schenck; also 3. a saw-fly, Amsais laeta F. 



70. R. sardous Crantz (=R. philonotis Ehrh). (Knuth, 'Bl. u. Insekt. a. d. 

 nordfr. Ins.,' pp. 18-20.) The flower mechanism and circle of visitors are as in 

 R. repens and its associated species. Warnstorf (Schr. natw. Ver., Wernigerode, 

 xi, 1896) describes a large hairy form at Ruppin, with hollow broadly trapezoidal 

 nectar-scales, but no secretion. Flowers slightly protogynous, anthers extrorse, ripen- 

 ing centripetally, and somewhat higher than the carpellary heads. Self-fertilization 

 is therefore rendered difficult, but not wholly excluded. Pollen-grains yellow, 

 spherical or ovoid, with three longitudinal furrows, tuberculated, 30-37 /*, in diameter. 



Visitors. H. de Vries (Ned. Kruidk. Arch., Nijmegen, 2. ser., 2. deel, 1875) 

 observed in the Netherlands the honey-bee; and MacLeod in Flanders noted 

 2 Syrphidae, 2 Muscidae, and one of the Siricidae (Bot. Jaarb. Dodonaea, Ghent, 

 vi, 1894, p. 178). 



71. R. arvensis L. (Hoffmann, 'Uber Sexualitat' ; Kirchner, 'Flora v. 

 Stuttgart,' p. 266.) Kirchner states that there is much variation in the size of the 

 flowers, in the order of development, and in the number of stamens and carpels. 

 The diameter of the sulphur-yellow flowers is 4-10 mm. When they open, the 

 stamens are at first directed inwards above the carpels, often completely covering 

 them, but as the anthers begin to dehisce upwardly and outwardly, the styles 

 elongate. These are beset with stigmatic papillae at the end, and along an inwardly 

 directed longitudinal line. Owing to the relative positions of pollen and stigmas 

 automatic self-pollination is hardly possible. In some flowers, however, the anthers 

 have dehisced while the stigmas are still situated below them, so as readily to 

 catch the falling pollen. But when such blossoms reach a later stage this cannot 

 happen, the flowers being erect, and the stigmas projecting above the anthers. The 

 number of stamens is usually 10-13, but not infrequently some of them degenerate, 

 so that the flower only possesses 5-2. They may even be entirely aborted, rendering 

 the plant gynomonoecious. These female flowers are much smaller than the herma- 

 phrodite ones, and the styles at the time of opening project from the corolla. 

 Hoffmann also observed markedly protandrous hermaphrodite flowers. Focke states 

 that R. arvensis is self-fertile (Abh. natw. Ver., Bremen, xii, 1893). 



Visitors. MacLeod observed in Flanders one of the micro-Lepidoptera and 

 2 small Muscidae as visitors (Bot. Jaarb. Dodonaea, Ghent, vi, 1894, p. 180). 



72. R. sceleratus L. (Knuth, 'Bl. u. Insekt. a. d. nordfr. Ins.,' pp. 20, 147.) 

 The numerous flowers of which the diameter is usually less than 1 cm. make 

 the plant conspicuous from a distance, in spite of the smallness of the individual 

 blossoms. Consequently many short-tongued insects seek the nectar, which is 

 secreted in a pit at the base of each petal. When the flower opens, the stamens 

 with anthers still unripe lie close to the carpels, but are not so high as the already 

 receptive stigmas. As the anthers dehisce centripetally the filaments bend away 

 from the carpels, approaching the horizontally expanded petals. When insect 

 visitors alight upon the carpels they effect cross-pollination, if otherwise self- 



