SAXIFRAGES (ROCKFOILS). 185 



in April, which are followed by the large green leaves. 

 The flowers are white. This species loves a moist, 

 sheltered spot and makes a fine ornament for the bog 

 garden. 



Retusa. — A dwarf species from Piedmont, with 

 purple flowers on stems an inch or two high in May. 

 The habit is close and tufty, like that of oppositi folia, 

 with which it is classed. Wulfeniana is considered 

 to be a deep purple variety of it by some authors. 

 These make charming cushions on the rockery. They 

 will thrive in loamy soil, and may be increased by 

 division. Wulfeniana is a precious plant, and likes a 

 hot sunny spot. 



Rocheliana is an Austrian species, a little tufty plant 

 of the Kabschia section, and therefore of the same class 

 as Burseriana, caesia, Boydi, etc. Its silvery rosettes 

 of foliage are very pretty, and the flowers, which are 

 white, and borne on stems about three inches high in 

 spring or early summer, are also attractive. There 

 is a variety of it called coriophylla, which has smaller 

 leaves. These precious little Rockfoils thrive in sunny 

 parts of the rockery in gritty loam. 



Stracheyi is a fine species of the Megasea group, 

 a native of the Himalaya, with pink flowers on strong 

 stems a foot or more high in spring, and large leaves. 

 It may be associated with cordifolia, crassifolia and 

 ligulata. 



Valdensis is a tufted Alpine, with large white flowers 

 on short stems in spring. It is suitable for association 

 with Burseriana and others of the Kabschia group, 

 forming neat, close cushions starred with blossom. 



