248 



Eue. Warming. 



Adventitious roots are frequently developed on the 

 prostrate shoots, but vegetative propagation does not take 

 place, or rarely does so, through their agency. 



Here also the habit of the plant is properly speaking 

 tufted; to what a high degree the length of the shoots is 

 dependent on the prevailing conditions, is evident from Syl- 

 vén's observations (Cerastium alpinum, pp. 299 and 300). 



Fig. 8. Cerastium alpinum. 

 A, Young plant (from cultivation); about Vi- B, Basal portion of the 

 cotyledons; buds are seen in both axils. C, Older plant (from cul- 

 tivation; the internodes are less elongated than in A ; after the cotyle- 

 dons, the typical Caryophyllaceæ-branching appears, first with a 

 vigorous shoot in the axil of the one leaf and a less vigorous in 

 that ot the opposite leaf, then with bud only in one of the axils of 

 the two opposite leaves; in A — C the hairs are omitted. D, A leaf 

 W'th its covering of hairs. E, Young shoot in spring. F, From 

 N. E.Greenland; winter-stage, 21. 5. 1908 (A. Lundager). A pair of leaves 

 with axillary shoot; there are no winter-buds nor any special covering 

 for the buds. G, Branch of Cerastium alpinum y cæspitosum (from 

 E. Greenland). Secondary roots are developed; the hairs are omitted. 



(E. W.) 



In nature the young plants appear to pass the winter "in 

 a rosette-like-stage," he has, however, found the form glabra 

 to develop in the first year" directly elongated internodes." 

 The young plants which had been reared under cultivation 



