44 Morten P. PorsiLp. 
p. 383, 1912. Here the variety is also mentioned, but new facts regarding 
its taxonomic position were not brought forward. 
Compared with A. pygmaeus, the var. Langeana Natu. is less 
tufted, the stems are slender erect, 10—15 cm. high, mostly with two 
stem leaves. Typical A. pygmaeus is densely tufted, more or less 
prostrate — ascending, but, when growing in moss, the stems be- 
come longer, 10—12 cm. The leaves are distinctly lighter-coloured 
and a trifle thinner. JESSEN gives the average thickness of the leaves 
of À. pygmaeus as 0.27—0.30 mm., whereas sections of the variety 
Langeana, made by me, averaged 0.22 mm. in thickness. The anatomy 
of the leaves and the disposition of the stomata are practically the same. 
Also in var. Langeana, the roots are mycotrophic. NATHORST suggests 
that the pedicels of the variety seem to be more pubescent than in the 
typical form, but I have not been able to find any difference when they 
were of equal maturity. The achenes are practically equal in size and 
shape. Generally, however, the styles of var. Langeana are straight 
or nearly so, whereas the styles of R. pygmaeus are distinctly recurved 
(see Jessen Le. p.382, WAnLENBERG Fl. Lapp., tab. VIII), but 
straightish styles are also sometimes seen in this species. 
In spite of the slight difference, except in the form of the leaves, 
var. Langeana Natu. seems not to be a mere ecologic form, but rather 
a geographical race, hitherto known from Greenland and alpine 
Gaspé, Québec. If it were only a form adapted to growth amongst 
mosses, it would certainly have been noticed long ago in Northern 
Scandinavia, where R. pygmaeus has been known for nearly 200 years; 
and then one should easily find it everywhere. But such is not the case, 
here at least. On many suitable spots it has been searched for in vain, 
whereas at its type locality, where also typical R. pygmaeus is abundant, 
it is always easily found. 
BIANCO LUNO A/S, KBHVN 
