UMBELLIFERAE 465 



self-pollination can take place, failing insect-visits. The anthers first dehisce in 

 j slow succession, but the stigmas mature so early that the last stamen is covered 

 1 with pollen when they have become receptive. The stigmas come automatically 

 j into contact with the pollen so as to bring about autogamy, which is completely 

 i effective. I observed it in the North Frisian Islands. Warnstorf says that occasional 



flowers are often purely female by degeneration of the anthers. The pollen-grains 

 i are pale yellow in colour, irregular, either bipyramidal or in the form of a pyramid 



with convex base, about 25/1, long and 18 //, broad. 



1090. H. americana L. 



Visitors. Henslow records minute Muscids for Kew Gardens. 



320. Sanicula L. 



Flowers white, andromonoecious, in small sub-globose umbels; with exposed 

 ! nectar. 



1091. S. europaea L. (Herm. Miiller, ' Weit. Beob.,' I, p. 303 ; MacLeod, 

 Bot. Jaarb. Dodonaea, Ghent, vi, 1894, pp. 257-9; Kirchner, 'Flora v. Stuttgart,' 

 p. 375; Schulz, 'Beitrage,' II, pp. 81-2; Kerner, ' Nat. Hist. PI.,' Eng. Ed., 1, II, 

 pp. 323-4; Francke, 'Beitrage.') Hermann Miiller states that there are 1-3 pro- 

 tandrous hermaphrodite flowers in each of the small umbels of this species, surrounded 

 by 10-20 purely male ones that mature later. The nectary of the small, bright- 

 reddish flower is a groove bounded by an annular ridge; nectar is secreted in 

 tolerable abundance. 



According to Schulz the male flowers may also occur in the middle of the 

 inflorescence, and mature before the hermaphrodite ones. 



Other investigators, e. g. Kerner and Francke, describe the flowers as proto- 

 gynous, so that the mechanism would appear to vary in different districts. Kerner 

 confirms Hermann Muller's statement that there are central hermaphrodite flowers 

 which first mature. The stigmas of these flowers at this stage can only be 

 xenogamously pollinated by insect agency. The filaments subsequently elongate 

 so as to bring the anthers to the same level as the stigmas. As, however, the 

 styles are upright, and the filaments directed obliquely outwards, the anthers and 

 stigmas do not come into contact. Though automatic self-pollination is thus 

 rendered impossible, yet, after the stamens have fallen off, there may be automatic 

 geitonogamy of the originally hermaphrodite flowers, for the styles diverge so as to 

 approach the anthers of adjacent flowers in the same inflorescence. 



Visitors. Herm. Miiller noticed small flies and small beetles (Meligethes). 

 MacLeod saw 2 short-tongued bees and an Empid in Flanders (Bot. Jaarb. Dodonaea, 

 Ghent, vi, 1894, p. 259). 



In Dumfriesshire, a Vespid, 2 Muscids, and a Syrphid were recorded (Scott- 

 Elliot, ' Flora of Dumfriesshire,' p. 74). 



321. Astrantia L. 



Flowers white or reddish in colour, arranged in simple umbels ; the concealed 

 nectar is secreted by an epigynous disk. The petals serve as a nectar-cover, being 



DAVIS. II H ll 



