CULTURAL AND DESCRIPTIVE NOTES ON THE GENUS SAXIFRAGA. 41 



higher Alpine regions, covering the most inaccessible peaks, 

 growing in fissures and on debris of rocks, at an altitude of from 

 6,000 feet to 9,000 feet. These mostly prefer limestone rocks, 

 although a large number also grow on granite, gneiss, dolomite, 

 marble, and even sandstone. Again, S. oppositifolia is found 

 growing on high mountains on the shady and damp side of rocks, 

 often covering large areas with a beautiful carpet. On the 

 other hand, S. petraea and S. hederacea inhabit deep, dark, and 

 damp caves of a very low temperature. S. Fortunei, S. pennsyl- 

 vanica, S. peltata, and others are found growing in swamps and 

 low and damp ground, whilst members of the section Megassea* 

 are found both on exposed hills and in valleys. 



The most favourable time for replanting and propagation, 

 either by division or seed, is in the early spring. A few of the 

 mossy Saxifrages and the more robust of the encrusted species 

 might be propagated almost at any time. The propagation by 

 division is best done in the open, in light sandy soil under 

 a hand-light. Under such circumstances the plants soon 

 make roots ; but some should be left here for at least a year 

 before being removed. Seeds should be sown early in February 

 under a bell-glass in light soil, and kept fairly damp ; the young 

 seedlings should be pricked out in pans or in a frame under glass, 

 and left there until they are large enough for planting or potting. 

 Plants raised in this way are more vigorous and less liable to die 

 than collected plants. The following are the best and most 

 distinct kinds of Saxifrages : — 



Sect. Euaizoonia, Schott. 



Plants belonging to this and the section Kabschia, as repre- 

 senting the encrusted species, although, as I mentioned before, 

 natives of high altitudes, and almost invariably found growing 

 on limestone, are easily managed, even in our smoky London 

 climate. Some of the more difficult subjects should be planted 

 on the rockery ; the more vigorous, such as S. longifolia, S. 

 Aizoon, S. Cotyledon, etc., do fairly well as border plants in light 

 soil mixed with pieces of limestone and sand, and some of these 

 make beautiful pot plants. 



S. longifolia, Lap. — This is perhaps the most popular and 

 certainly one of the finest of this section. The leaves are long, 

 glaucous, and arranged in rosettes. The flowers are pure white, 



