198 BRITISH FLOWERING PLANTS chap. 



insect pressing its head to the flower touches them with 

 one side and the stigma with the other. It is a bee- 

 flower, but the flowers often hang in such a manner that 

 the pollen falls on to the stigma and fertilises it. 



R. Grossularia (Gooseberry) is slightly protandrous. 

 The cup of the flower is somewhat deeper than in the 

 preceding species, and the honey is also protected by stiff 

 hairs on the pistil which reach across nearly to the 

 petals. 



R. nigrum. — The flower is arranged like that of 

 R. rubrum, but the calyx is more bell -shaped, and 

 access to the honey is only possible to insects with 

 a proboscis. Insect visits, however, are not numerous, 

 and it is often, perhaps generally, self-fertilised. 



SAXIFEAGACEiE 



Saxifraga 



The flowers are white or yellow, often sprinkled with 

 purple, more rarely rose or blue. The outer wall of the 

 ovary secretes honey, which is generally quite exposed, 

 in consequence of which the flowers are richly visited 

 by insects. They are, as a rule, protandrous, but a few 

 species are protogynous. The fruit is an upright 

 capsule, and the seeds are jerked out by the. wind. 



S. Geum. — The stamens are arranged round the 

 flower, with the unripe pistil in the centre. After the 

 anthers have shed their pollen, they shrivel up, while 

 the stigmas separate and occupy the positions pre- 

 viously filled by the stamens. 



S. oppositifolia agrees in essentials with S. Geum. 

 Engler describes the flowers as sometimes protogynous, 

 sometimes protandrous ; Ekstam found them protan- 

 drous in Nova Zembla, while, according to Ricca, they 

 are homogamous ; according to H. Miiller on Piz Umbrail 

 and the Albula, to Warming in Greenland, and Lind- 



