ROCK GARDEN PLANTS 43 



white flowers and clustered yellow stamens, is one of 

 the best. R. glacialis, in the coolest positions, and R. 

 anplexicaulis (White Buttercup) are good for rock 

 gardens. 



Sanguinaria. Bloodroot. A very desirable plant. 

 S. canadensis forms dense clusters of large glaucous 

 leaves, on which numerous white flowers with yellow 

 stamens rest like miniature Water-Lilies. Division. 



Saponaria. Soapwort. The rosy-flowered S. ocymoides 

 is a beautiful plant for mantling the edges of rocks. 

 Poor, dry soil. 



Saxifraga. Rockfoil. Perhaps the best known of all 

 rock plants. S. Cotyledon (Pyramidal Saxifrage), S. 

 longifolia, S. oppositifolia, S. umbrosa (London Pride). 

 Described elsewhere. 



Sedum. Stonecrop. Hardy dwarf plants for rock 

 crevices and the higher ledges. S. acre (Wall Pepper) 

 grows freely on walling, and is bright by reason of its 

 vivid yellow flowers. S. stoloniferum (Purple Stone- 

 crop), with large leaves, and S. Sieboldi, useful for 

 draping the edges of stones, are among the best. 



Sempervivum. Houseleek. Dwarf succulents, thriving 

 in the poorest soil. The Cobweb Houseleek (S. arach- 

 noideum) is exceedingly quaint, with its myriad silver 

 leaf rosettes covering the ground like a web. S. triste, 

 with red leaves, is distinct. Offsets. 



Sikne. Catchfly. Invaluable for rock gardens. The 

 Alpine Catchfly (S. alpestris) is a hardy white-flowered 

 kind. S. virginica (Fire Pink), though impatient of 

 overmuch moisture, is very beautiful, with its vivid 

 scarlet flowers borne above the trails of prostrate foliage. 

 Seed. 



Soldanella. In a moist, deep soil between the higher 

 rocks, Soldanellas are delightful. S. alpina has bell- 

 shaped flowers of a pale blue colour, the carpet of 

 feathery foliage in this variety giving an added 



