987 



self-pollinated, few being wind-pollinated^. The habitat on the 

 open clift' renders the flowers rather conspicuous and easily found 

 by insects. FHes are the most frequent insect-visitors, but some 

 species (e. g. Silene ac(uilis) are frequented by insects with a long 

 proboscis. 



(2*^.) The formation of the moist and shady crevices, 

 the ombrophile chomophyte formation. This consists of a 

 number of species which require for their growth a certain amount 

 of moisture in soil and atmosphere, and protection from excessive 

 insolation. It is at once evident from their leaf-structure that, al- 

 though not hydrophyles, the piants are unable to endure dessica- 

 tion. The general type of leaf has a thin cuticle, an open structure 

 with rounded cells, and no great development of palisadc-tissue. 

 These features are best seen in the dicotyledonous characler-species 

 of the formation, viz: Cardamine siluatica, Cochlearia officinalis (formå), 

 Saxifraga riviilaris, S. stellaris, S. nivalis, Epilobiiim lactiftoriim and 

 E. alsinifolium. The same may he said of the characteristic ferns: 

 Athijriiim filix foemina, Aspidiiim filix mas, Asp. dilataium, Cysto- 

 pteris frayilis and Hijmenophijlliim peltatiim. The grasses which I 

 consider to belong to the formation are Poa nemoralis, Aira alpina 

 and a giant form of Festuca ovina vivipara. The two last mentioned 

 species appear in other formations in other forms; when they grow 

 in moist crevices they have comparatively broad leaves and a tall 

 loose habit, and both are distinctly pseudoviviparous. Poa nemoralis 

 is a grass of the woods in Denmark and has a very delicate leaf- 

 structure. Attention is here called to the general rule that when 

 the ombrophile chomophytes named above occur in the Central- 

 European region, it is as piants of the woods; for example several 

 of the ferns and Cardamine silvalica. Cochlearia officinalis is note- 

 worthy as a plastic species, or, to put it more correctly, the spccific 

 name conceals a whole series of elementary species'. The plant 

 appears on the Færoes in nearly every formation with a loose 



^ The formation of seeds in Alchimillae is apogamic. 



- I-'or several years (see also Ostenfeld 1907, p. 850) 1 have cultivated in the 

 hotanical garden at Copenhagen Cochleariae grown from seed collected in different 

 countries. Each form has there retained its peculiarities throughout several gene- 

 rations and is easily distinguished by its habits as a whole, althoiigh it seems ex- 

 tremely difficult to give a morphological description with distinguishable and fixed 

 characters. The forms cultivated included one from the coast-cliff of the Færoes, 

 a second from the rock3'-flat, and a third from the formation considered here; 

 they have remained quite distinct from each other. 



