82 Knud Jessen. 



Bubus chamæmorus L. 



Lit. Warming, 1886, a. Lindman, 1887. Kihlman, 1890, 

 pp. 55, 113. Hartz, 1894, p. 7. Norman, 1895. Kolderup 

 Rosenvinge, 1896, a. Kruch, 1897. Andersson and Hessel- 

 man, 1900. A. Cleve, 1900, p. 47. Poppius, 1903. Sylvén, 1906. 



Rubus chamæmorus is circumpolar, but thrives also in 

 temperate regions in Asia, America and Europe, where in 

 many places it must most properly be regarded as a relict. 

 It occurs almost everywhere in damp localities, and grows 

 by preference on the loose surface of bogs and marshes. A 

 few exceptions from this rule are however known, the plant 

 in Arctic Norway, according to Nordman, growing in dry 

 localities furthest out towards the sea and especially at some 

 height above it; an explanation of this phenomenon has been 

 sought in the fact that the air from the sea is extremely 

 damp. In Greenland also, where it only occurs in the coas- 

 tal districts and on islands in the skerries, it grows on rela- 

 tively dry and heath-like tracts. 



The aerial shoots are vegetative or vegetative-floral. 

 They usually bear 1 — 3 foliage-leaves and are terminated by 

 a solitary flower or by a dead bud enclosed in the sheath of 

 the uppermost foliage-leaf. The aerial shoot usually has 

 at its base a few scale-leaves with intervening short inter- 

 nodes (Fig. 32, C). The uppermost of these scale-leaves are 

 doubtless as a rule situated above the surface of the bog, 

 and often from the axils of the lower arise during summer 

 scale-leaf-bearing shoots which will next year produce aerial 

 shoots. Consequently, the plant has a two-years develop- 

 ment. During autumn the scale-leaf-bearing shoots form a 

 distinct resting-bud which is situated at the surface of the 

 bog. If the shoot arises from a point which is situated at 

 some depth in the bog it assumes a more or less decided 

 wandering stage before it enters into the assimilatory or 

 ultimately floral stage; the shoot to the right in Fig. 32, D 



