1917.] THE FLORA OF THE SWISS ALPS 51 



The beautiful alpine Poppy (Papaver alpinum L. var. Sendtneri 

 Kerner) follows another system of resisting the menacing soil move- 

 ments of its habitat, opposing itself with big clusters of crowded 

 roots against the moving stones (Fig. 25). It is a rare inhabitant 

 exclusively of calcareous debris. It is a delicious spectacle to see hun- 

 dreds and hundreds of little islands between the bare stones gar- 

 nished with their delicate white flowers. 



One of the saxifrages, the genus so rich in alpine species, the pur- 

 ple Saxifrage (Saxifraga oppositifolia L.), is widely Arctic-Altai 

 element of the alpine flora, using the two modes of growth, creepers 

 and compact clusters. It has wandered once in the glacial time with 

 the increasing glaciers to the foreland of the Alps; and after the 

 glacial epoch, as the glaciers retreated to their present state, it has 

 subsisted in isolated colonies upon the gravel along the shore of the 

 Lake of Constance, as a typical glacial relic. 



Another kind of alpine debris, a resting flat stony soil, saturated 

 with snow, is inhabited by some high alpine plants, the Gentian 

 (Gentiana bavarica L.) (Fig. 26) and the glacial Buttercup (Ra- 

 nunculus glacialis L.). The buttercup is a circumpolar arctic ele- 

 ment ; it forms often true gardens of white and rose flowers in ab- 

 solutely glacial conditions, up to 14,250 feet, the absolute upper lim- 

 it of flowering plants in Switzerland (Fig. 26). It is a noticeable 

 fact that this most resistant plant shows no visible adaptation to the 

 extreme conditions of its glacial stations ■ it has a smooth somewhat 

 fleshy stem, glabrous leaves, forms no cushions : we have here one of 

 those instructive cases where the power of resistance lies in the con- 

 stitution of the living substance, is purely physiological, and shows 

 no morphological expression. Similar stations upon wet sand in the 

 high alpine belt are adorned with the rose cushions of Androsace 

 alpina (L.) Lam. 



The last ecological group of the alpine plants are the rock- 

 plants, the inhabitants of bare rocks. We can here distinguish, after 

 the mode of fixing itself upon the rock, two sub-groups : Lower 

 (cr} r ptogamic) plants, lichens and algae, are clinging directly to the 

 bare rocks, perforating its surface with their stone-dissolving cells, 

 aiding erosion, preparing the soil for higher plants. The other 

 group, including mosses, ferns, and flowering plants, is confined to 

 the sediments of detritus in fissures or upon little bands of rock 

 (chomophytes). 



One of the most exclusive of our alpine rock-plants is the rock- 

 Potentilla (Potentilla caulescens L.), which thrives only in the fis- 

 sures of vertical rock-walls, penetrating deeply the rock and form- 

 ing in the fissures often quite a texture of entangled rootlets. It has 

 no adaptation at all against drought ; it is a typical mesophyte, and 

 therefore a proof of the fact that rock stations are not necessarily 

 dry ones ; the rock on the contrary is often quite a reservoir of water. 

 Also the yellow Primula (Primula auricula L.) is confined to cal- 

 careous rocks. 



