II ORASSULACE^ — RIBESIACE^. 197 



S. dasyphyllum. — This species is also said by some 

 authorities to be protandrous, but the stigmas are said 

 to ripen earlier in mountain districts, and, according to 

 Kerner, the anthers of the stamens opposite the sepals 

 open with the flower and fertilise their own stigmas. 

 Those of the series opposite the petals ripen later, and 

 as the stigmas are then withered, their pollen is, no 

 doubt, intended for cross-fertilisation. 



S. villosum. — The flowers of this species are protected 

 by the stalks being clothed with adhesive glands. 



Sempervivum 



The leaves are succulent, serving for water-storage, 

 as in Sedum. 



S. tectorum (House Leek). — The flowers are pro- 

 tandrous, but not so much so as to exclude self- 

 fertilisation. 



RIBESIACE^ 

 ElBES 



There are four British species. One, the Gooseberry 

 {R. Grossularia), has prickly stems ; JR. alpinum has 

 dicecious flowers and red fruit. In the last two the 

 flowers are complete ; one (R. rubrum) has red, the 

 other {R. nigrum) black fruit. It is doubtful, however, 

 whether any of them except R. alpinum are really 

 native. The flowers are greenish-yellow, yellow, or red, 

 with more or less concealed honey. 



R. alpinum. ^ — The petals are very small. The calyx 

 forms an open shallow saucer, which secretes honey. 

 The flowers being dioecious, self-fertilisation is out of the 

 question. As usual, the male flowers are rather larger 

 than the female. 



R. rubrum. — The flowers are homogamous and green- 

 ish-yellow. The calyx is less widely open than in the 

 preceding species. The anthers are so arranged that an 



