294 THE AL P JNE FLORA 



which is easily attacked and injured by frost. Propagate 

 by cuttings and seed. 



The genus is distinguished by a five-toothed calyx, 

 long-clawed petals, three styles, and a six-valved capsule 

 which opens at the top. 



S. acaulis* (PI. XXI). (Cushion Pink). A close-packed, 

 caespitose clump, forming a cushion of green, composed 

 of innumerable branches crowded one upon another, 

 and terminated at an equal height by rosettes of tiny, 

 narrow, linear-subulate leaves, ciliate at the base, and 

 bearing at the summit flowers of a charming rose colour, 

 with 5 petals slightly crenated, and attached to the cushion 

 in such a way as to cover it almost completely, so well 

 indeed that the foliage cannot be seen through the shining 

 garment above. The stalk on which the flowers is carried 

 is very short, from ^ to 2 in. July-August. Rocks, 

 moraines, and dry pastures of the Alps (i5oo-3ooo m.). 

 There are several varieties, of which one, S. exscapa, has 

 a small, sessile flower, directly attached to the branch, and 

 an almost globular seed-vessel, which does not stand above 

 the divisions of the calyx (in acaulis the capsule is oblong 

 and exserted). S. bryoides differs from acaulis in non-crenate 

 petals and a somewhat shorter capsule. All three forms 

 are found with white flowers, and I have found on the 

 Cenisian Alps a fine variety of acaulis with double flowers, 

 like to miniature roses of the most beautiful vivid carmine. 



Culture: the various cushion-pinks grow in a sunny 

 position, a dry, sandy, well-drained, stony soil, with pre- 

 ference for a rockery or old wall. 



S. alpina is closely allied to the common S. inflata* of 

 our fields, but the stems are prostrate and stoloniferous, 

 the leaves very smooth, and the flowers larger. Found 

 among stones. 



S. rupestris (PI. XXI). A slender plant with many, thin 

 stems, divided and branching from the base; leaves nar- 



