336 



ALPINE FLOWERS. 



Part II, 



time immemorial on housetops and old walls, is well known 

 to everybody. It is needless to describe the culture of a 

 plant which thrives on bare stones, slates, and in the most 

 arid position. It, like some less known species, may be used 

 in flower-gardening for forming dwarf borders, &c., though it 

 would be better to give a position in gardens to somewhat rarer 

 species. It varies somewhat, a glaucous form called rusticum 

 being one of the most distinct. 



SEMPERVIVUM CKLXMiSSXiM.— Glaucous Houseleek. 



The Sempervivum now becoming very common in cultivation, 

 under the garden name of .S". californicum,' is by some con- 

 sidered a very glaucous variety of S. tectorum, by others the 

 same as the French S. calcareuvi ; it is probably the last, but 

 not having as yet met with the plant in flower, I am not able to 

 determine this point with certainty. Of one thing, however, we 

 may be assured — that no finer Houseleek has been introduced, 

 and that, if not very nearly related to our common one, it is 

 certainly as easily grown and as hardy as that much-enduring 

 old plant. Planted singly, the rosettes of S. calcareum some- 

 times attain a diameter of nearly five inches, and as the leaves 

 are of a decided glaucous tone, distinctly tipped at the points 

 with chocolate, it is deservedly very popular for forming edgings 

 in the flower-garden. It is also admirable for the rockwork, is 

 easily increased by division, and thrives in any soil. 



In addition to the preceding, which are among the most distinct 

 and ornamental of the Houseleek race, there are a great number 

 of species, or so-called species, wild in Europe, many of which are 

 often cultivated in botanic gardens. In the following list the 

 more ornamental kinds are marked with an asterisk. 



