substratum, and it differs greatly in its appcarance in thc difTerent 

 habitats. 



The vegetative organs of piants of this formation aie mainly 

 cæspitose and spot-bound, but several of the species occurring in 

 moss-carpets have some capacity for wandering, e. g. the two Epi- 

 lobia and in a small degree Saxifraga stellaris. Fruiting and spore- 

 production take place abundantly. The dicotyledons {Epilobiiim spp. 

 excepted) have open and generally white »tly-tlowers«, which appear 

 early in the year. 



The ombrophile chomophyte formation has its home in the 

 moist and sombre parts of the ravines; here, in many piaces, water 

 oozes over luxuriant moss-carpets, studded with flowering piants, 

 while here and there patches of Nostoc carneiim and filamentous 

 green-algæ cover the mosses; at olher piaces the ferns and some 

 of the phanerogams form a tall dense growth with a dull or deep 

 green colour, and no space is left for mosses. 



(3*^.) The formation of the luxuriant warm and sunny 

 led ges, the thermophile chomophyte formation. This oc- 

 curs in the open sunny higher parts of the ravines and on favour- 

 ably exposed rock-ledges, and there the many handsome flowers give 

 the rocks an attractive appearance. It includes a large number of 

 species, but I only regard those as characteristic which do not 

 attain their full development except on well-watered cliff-terraces 

 with a good exposure, or those species which are more frequent 

 and more conspicuous there, while of very secondary importance 

 in all other habitats. The following species are included in the 

 formation: all the Hieracia (21 species), Hijpericiim piilchriim, Ge- 

 ranium silvaticam, Chamaeneriiim angiistifoliiim, Epilobiiim nion- 

 taniim, Polygala viilgaris Ballii, Alectorolophiis groenlamliciis, Riibiis 

 saxatilis, Angelica siloeslris, Draba incana, Spiraea iilmaria, and the 

 Monocotyledons, Liiziila silvatica, Carex flacca and Feshica riibra 

 planifolia. The most conspicuous and commonest species are the 

 Hieracia, Luziila, Geranium siluaticiim, and the large Fesliica. 



These character-plants include species with subterranean root- 

 buds or wandering-shoots (Chamaeneriiim cmgustifolium, Carex flacca 

 and Festuca riibraj, others with epiterranean runners (Rubiis saxatilis): 

 but the majority are spot-bound — all the Hieracia, Geranium sil- 

 vaticiim, Liiziila silvatica, etc. Completely detached from all the 

 others we have the annual parasitic plant Alectorolophiis groenlan- 

 diciis. Most of these species have a soulhern distribution, and this 



