THE HIGH ALPINE ANDROSACES 181 



peculiarities of the calyx and fruits. Its cushions 

 are commonly mistaken for those of Silene acaulis, 

 but they are more densely tufted, more spherical in 

 shape, and the leaves shorter. The flowers are also 

 smaller and paler. It is generally believed to be 

 confined in Switzerland to the High Alpine region. 

 It is not a British plant. 



The High Alpine Androsaces. 



The Androsaces of the lower Alpine region 

 described in Chapter III. are typical rosette plants. 

 Yet all the High Alpine species possess the cushion 

 habit. The Swiss Androsace {Androsace helvetica, 

 Gaud., natural order Primulacese, the Primrose family) 

 (Plate XXXIV., Fig. 1) is a typical example. This 

 plant builds cushions, resembling an hemisphere in 

 shape, and sometimes 6 inches high. These are formed 

 by a large number of crowded branches, each branch 

 clothed with very small, blunt, over-lapping leaves, 

 which form compact, cylindrical, bud-like growths at 

 the ends of the branches. The leaves are covered 

 with simple hairs. The flowers are borne on very 

 short stalks, the corollas being white with a yellow 

 centre. This plant is not uncommon in the fissures 

 of calcareous rocks at great elevations. The cushions 

 are said to reach a considerable age, 50 to 60 years 

 being reported in one case. 



The much rarer Imbricated Androsace {Androsace 

 imbricata, Lam.) builds cushions similar to those of 

 the Swiss Androsace. They are, however, easily 



