RUBIACEAE 547 



Kirchner describes the small white inconspicuous flowers of this species as pro- 

 tandrous. The stamens, however, do not bend back out of the flower, so that 

 when the stigmas mature and diverge later on, they always touch the anthers, 

 which, though dry, still carry pollen, so that automatic self-pollination is constantly 

 secured. Darwin says that this is followed by the setting of fruit. 



Visitors. I observed the po-dvg. hover-fly Syritta pipiens L. 



In Dumfriesshire a wasp, an ichneumon fly, and a Muscid were recorded 

 (Scott-Elliot, 'Flora of Dumfriesshire,' p. 87). 



1253. G. purpureum L. (Schulz, 'Beitrage,' III, p. 97.) Schulz states that 

 the stamens are erect in the dark brownish-red flowers of this species, so that the 

 anthers lie almost immediately above the stigmas, which mature simultaneously. 

 By the fall of pollen autogamy is inevitably brought about. 



Visitors. These are hover-flies, with small wasps and other little Hymenoptera, 

 which usually effect self-pollination, though sometimes they undoubtedly bring about 

 crossing. 



1254. G. tricorne Stokes. (Herm. Miiller, '\Veit. Beob.,' Ill, pp. 70-1.) 

 Herm. Miiller states that nectar is abundantly secreted in this species, but 

 the solitary white and yellowish-white flowers are so small that they do not 

 receive many visitors. Automatic self-pollination therefore regularly takes place: 

 the stamens do not bend outwards, but their anthers remain above the stigma, 

 which matures simultaneously. Kerner says that automatic self-pollination is 

 brought about by the anthers touching the stigmas as a result of incurving of 

 the filaments. 



Visitors. Herm. Miiller only observed a Muscid (Anthomyia), nect-lkg. 



1255. G. lucidum All. (=G. corrudaefolium Vi'lL). (Schulz, 'Beitrage,' II, 

 pp. 97-8.) Schulz states that the flower mechanism of this species resembles that of 

 G. Mollugo. Protandry more or less marked. Self-pollination is usually prevented 

 by outward curving of the stamens. The styles elongate considerably during 

 anthesis. 



Visitors. Schulz observed many small insects (flies, small Hymenoptera, 

 beetles), which frequently effected self-pollination. 



1256. G. rubrum L. (Schulz, op. cit.) The flowers of this species are red or 

 dark red in colour, and Schulz describes them as homogamous. Since the stamens 

 bend outwards automatic self-pollination is not readily effected ; but it is the only 

 important means of fertilization, for Schulz, in spite of repeated observations in 

 favourable weather, only saw 2 hover-flies visiting the flowers. 



Visitors. Vide supra. 



1257. G. rubioides L. (Kirchner, 'Beitrage,' p. 61.) The plants of this 

 species examined by Kirchner in the Berne Botanic Garden were protandrous. 

 The flowers are white and shaped like a shallow funnel : the stamens are at first 

 erect, but later on bend outwards, and their anthers drop off. It is only when this 

 has taken place that the styles elongate and the stigmas diverge. 



1258. G. helveticum Weigel. (Schulz, ' Beitrage,' II, p. 99.) The whitish- 

 yellow or greenish-yellow flowers of this species spread out into a star of about 



n n 2 



