Caryophyllaceæ. 247 



like, without, however, being in reality "wandering." Slen- 

 der, adventitious roots may occur in the interior of the 

 cushions. 



The Winter-stage. The same is the case here as in 

 all the other Arctic Caryophyllaceæ : the buds are open; in 

 the autumn there are fresh, green leaves, but during the 

 winter many, or we may say, the majority of them, wither; 

 nevertheless, the species may be called evergreen. At the 

 commencement of spring, or of the time for the opening 

 of the buds, the remaining leaves wither quickly. The degree 

 of greenness of the plant is dependent on the station, espe- 

 cially if this is snow-covered or not. 



D. The Cerastium alpin urn type. 



To this may be referred: Cerastium alpinum, C. cæspi- 

 tosam, C. nigrescens, C. Regelii and Arenaria ciliata. 



These also are typically spot-bound species, but there 

 are no monopodial shoots, these being now if anything 

 long-shoots with elongated internodes, even if the prevailing 

 conditions may sometimes produce semi-rosette-like forms. 

 Here also the internodes are shortest at the base of the shoots, 

 and as branches arise more particularly from the base, meso- 

 corms of the usual type are developed; the barren or flower- 

 ing branches are held together by the primary root which 

 remains during the whole life of the plant, but the branches 

 of the mesocorm are not particularly close-set, and the basal 

 shoots are often lying immediately upon the ground, spread 

 out in all directions (cf. Fig. 9). This is probably an instance 

 of psychrokliny, i. e. the direction of the stems is induced 

 by the low temperature in accordance with Voechting's 

 view. Added to this, the ground may possibly have been 

 damp and this may have produced root-development; the 

 pressure of the snow covering may also have had a part in it. 



