210 MARSH PLANTS 



those which float or project above the surface of the 

 water. These Water Ranunculi are entirely absent 

 from the Swiss Alpine region. Their place is taken by 

 such species as the Aconite-leaved Buttercup, which is 

 extremely partial to damp, but not too wet, soils. In 

 Plate XL. a photograph of an Alp covered with this 

 plant is seen. But it will be noticed that it does not 

 grow everywhere. It is distributed in bands, and 

 these bands represent the portions of the pasture 

 where the soil is dampest. The higher and drier 

 areas are unoccupied. Thus we have here a veritable 

 hygrometric chart of an Alp, the lines of highest 

 water contents being indicated by this plant. Similar 

 zones may also be frequently observed in Alpine 

 meadows, traversed by one or more damp ditches or 

 depressions, which are, as a rule, marked out as bands 

 of pure white by this Buttercup. 



Ranunculus aconitifolius is a large, highly 

 branched, spreading plant, the leaves resembling 

 those of the Winter Aconite (Eranthis). A variety 

 of this plant, very similar in many respects, but with a 

 leaf like that of a Plane (Platanus), is by some 

 regarded as a distinct species (R. platantfolius, Linn.). 

 It, on the contrary, occurs chiefly in fairly dry 

 situations in the Alps. 



THE BUTTERWORTS. 



The Butterworts, members of the genus 

 Pinguicula, belong to an order of insectivorous 

 plants, the Lentibulariacese, which stands near to the 



