THE HIGH ALPINE SAXIFRAGES 185 



plant contrasts rather markedly with those already 

 described. The flowers are borne singly, and are 

 shortly stalked. As a rule, the corolla is entirely 

 absent, or, if present, the petals are very reduced and 

 minute. The sepals forming the conspicuous portion 

 of the flower have membranous margins. 



The other species, Alsine aretioides, M. K. { = A. 

 octandra, Schur.), is confined to calcareous soils in 

 Canton Valais. It builds similar cushions. The 

 flowers in this case possess petals which, like the 

 sepals, are four in number, while there are eight 

 stamens, an unusual occurrence in this order of 

 plants. 



The High Alpine Saxifrages. 



Many of the Saxifrages, as we have seen (Chapter 

 III.), are typical rosette plants. A few form cushions 

 by a close aggregation of bud-like shoots. Such ; 

 species are not, however, confined to the High 

 Alpine region, but also occur at lower elevations. 



Sometimes in the High Alpine region Saxifraga ' 

 moschata, Wulf ( = /S'. varians, Sieb.), builds cushions, 

 though the plant is only tufted at lower altitudes.) 

 Saxifraga bryoides, Linn., which probably is simply 

 a High Alpine variety of the Rough Saxifrage \ 

 {Saxifraga aspera, Linn.) (see p. 81), forms cushions 

 by an aggregation of many bud- like shoots, arising in 

 the axils of the leaves of older branches. The 

 yellowish-white flowers are borne on erect shoots. 



We have ah-eady discussed the Purple Saxifrage 



