The Flora of Disko Island and Adjacent Coast of West Greenland. 121 



published his "Andet Tillæg" to Lange he further reduced groenlandi- 

 ciim to a variety coordinate with decumbens and palnstre a, ep. p. 691. 



The reduction of L. groenlandicum to a variety is, however, in direct 

 opposition to the view of modern American florists and taxonomists. 

 Having the profoundest knowledge of the plant from their resear- 

 ches in nature, they without any exception classify it as a separate 

 species. And, we may add, as all modern dendrologists do, also in 

 Europe where the plant still everywhere preserves its different aspect 

 under cultivation; (see for instance C. K. Schneider: "Hlustr. Handb. 

 der Laubholzkunde" II. 1912 p. 469). As will be seen by our investi- 

 gations we cannot but support this view. 



Regarding the other Ledum in Greenland 1 (i. e. M. P. P.) cannot 

 see but onetaxonomic unit in it. I must confess that its variations 

 on favourable habitats tend to develop larger leaves, but on the other 

 hånd I never found piants like typical specimens of L. palnstre from 

 Northern Europe. There always remains a certain characteristic habit 

 giving it a different appearance. And as the geographical features 

 seemed to support my view of L. decumbens as specific distinct from 

 L. palnstre^ a doser investigation of a large material became desirable. 

 As our home in Greenland is situated far to the north of the area of 

 L. groenlandicum and as our material of herbal specimens of this species 

 and still more of L. palustre, was too scanty, we applied to the Trustees 

 of the Botanical Museum at Copenhagen and obtained a large material. 

 As form and size of the leaves hitherto yielded the most conspicuous 

 distinguishing characters, an investigation of those points was chosen 

 as our main object, the more so because time was scarce, the printing 

 of our M. S. had been begun. This investigation was carried out by 

 E. P. alone. 



The distinguishing characters of Ledum palustre^ L. decum- 

 bens and L. groenlandicum. (By A. E. P.) 



In order to ascertain the size and form of Ihe leaves of Ledum 

 I investigated the material preserved in the herbariums of the Arctic 

 Station in Greenland and of the Botanical Museum at Copenhagen. 

 For the great majority of specimens I took the determinations, as they 

 were left by the several collectors, only of a slight number of specimens 

 have I altered the determinations, after having found a new distinguish- 

 ing character (see belowj. For the investigation a well developed 

 year's shoot of every specimen was taken and the leaves were measu- 

 red: the length without the pet i ole, the breadth without the 



