iv.] CRASSULACEJE, RIBESIACEsE. 105 



CRASSULACE^;. 



Of this order there are four British genera : Tillaea, 

 Cotyledon, Sedum, and Sempervivum. The first two 

 contain a single species each. Of Sedum we have 

 nine species. Though the flowers are small, yet from 

 the localities they occupy, and from their bright 

 colours they are somewhat conspicuous, and are visited 

 by many insects for the sake of their honey, which is 

 accessible even to those with short tongues. Some 

 (S. acre, reflexum, and telephium) are proterandrous,. 

 while ,S. atratum, according to Ricca, is proterogy- 

 nous ; and 6". rhodiola is dioecious. 



RIBESIACE^E. 



This order consists, as far as Britain is concerned, of the genus Ribes, 

 containing four species, the Gooseberry (R.grossulariata), Red Currant 

 (R. rttbrum), Black Currant (R. nigrum), and Mountain Currant (A*. 

 alpinum). They all supply honey. R. grossulariata is proterandrous, 

 and is said to have lost the power of self-fertilisation. In R. rubrum 

 and R. nigrum the stamens and pistil come to maturity simultaneously. 

 R. alpinum y on the contrary, is dioecious ; and it is interesting that, 

 according to Miiller, this species is more frequented by insects than any 

 of the others. 



SAXIFRAGACE^E. 



An extensive order, ranging nearly over the whole 

 world, but represented in Britain by only four genera^ 

 Saxifraga, Parnassia, Drosera, and Chrysosplenium. 



The species of the genus Saxifraga are melliferous^ 

 and proterandrous. Bergenia (Saxifraga) crassi- 

 folia, which, however, is not British, though frequently 

 grown in gardens, is according to Engler, protero- 

 gynous. In Chrysosplenium the anthers and stigma 

 ripen simultaneously. Parnassia palustris, as its name 

 indicates, inhabits wet and boggy places. It has ten 

 stamens, of which however five only bear anthers. 



