Nol 
126 Morten P. Ponsitp. 
N 
Poland; Niosikop:- tat re rant eee 5 
Sweden, Vastervik, Liebmann............ Dd 
Bapland: leas Demboll ese ree ee 6 
inland: -Abo; Holmen: sete eee 10 
Poland, Debelowo, Raciborski............ 5 
Lapland, Bosekop, Warming ............. 6 
— _— Hartman cee eee 6 
— Sakkabani, Warming ........... 6 
Detland @hicd- sb unse. ore aera eee 6 
Germany, Brandenburg, A. Lange ........ 6 
— = Jeliances cee aye 
Austria inferior, Spritzenhofer............ 5 
PIASteessiaes Wee DIS bit tee eee ee eee 5 
Hinland Nvidnd Spee te ote eee 6 
sweden. Hartman cc oe e aon eae toe ee 5 
Russia, White Sea Island, Pohle .... 10 
Average of 184 measurements on 32 
SPECIMENS a eee ee ee 
Results of the investigations. 
Summarizing the results of the measurements listed above, 
. L. decumbens, Greenland 40 1 
specimens, 290 measurements 7—12,79—21 
. L. decumbens, Arctic America 
and Siberia 11 specimens, 68 
MCASITEMENUSE- eee oe 14,41 
L. groenlandicum, South Green- 
land 40 specimens, 308 measu- 
TEMEUUS Howe eee Seite ee ee 11—20,04—35 
. L. groenlandicum, Boreal Ame- 
rica, 8 specimens, 50 measure- 
AMONUS ayy suse ets cesar tone 20,77 
. L. palustre, Boreal Europe 32 
specimens, 184 measurements 15—27,30 

1,5 

E b bl 
18,1] 2,1 8,62 
32,0 3,7 8,65 
30,0 3,4 8,82 
33,7 3,8 8.87 
19.0 2,1 9.05 
19,9 2,2 9,07 
19,6 DA, O35 
20,0 PANE Tbe sy 
31,0 3,2 9,67 
28.5 2,9 9,83 
20,0 1,9 10,52 
26,6 2.5 10,64 
43,0 3,7 11,62 
37,0 3,1 11,93 
35,2 2.9 12-57 
23,3 1,6 14,56 
27,20 3.24 8,41 
we find: 
b lb 
1—1,85 3—6,91— 
1,80 8,03 
8,83 

3,246 
3—6,31—13  1,5—3,18—' 
3,14 
58,41 — 
By comparing the lists I and III we see that the two Greenland 
species of Ledum in the great majority of cases will easily 
be distinguished by the shape of the leaves alone, L. groen- 
landicum being — as was known before — a more broad-leaved form. 
However, we must admit that in some cases the lists overlap, i. e. there 
