Rit (Vísindafélag Íslendinga) - 01.06.1975, Page 53
19. C. Lyngbyei — C. rariflora — C. chordorrhiza sociation
(Tab. V A-B 1-5)
This sociation distinguishes itself from those mentioned ahove in
that it is richer in species and C. chordorrhiza characterizes it hoth
in physiognomy and covering. The terrain has the appearance of
a flæðimýri, since the ohservations are only made in old alluvions.
Number 1 and 2 in Landeyjar, no. 3 in fhe delta area of Jökulsá
m Dalur, and no. 4 in Bræðratunga at Hvítá. The surface is level
everywhere, the terrain rather wet, hut the water appears to have
stagnated altogether. Bog iron occurs in great quantity everywhere
especially in no. 4. Sphagnum occurs in no. 3 and 4. This may
well be an intermediate stage between flæðimýri and flói. E. per-
centage is high, as is HH percentage. C. Lyngbyei is dominant,
ðut C. chordorrhiza and C. rariflora give the sociation unmistak-
ahle flói characteristics.
20. C. Lyngbyei — C. rariflora — Salix glauca sociation
(Tab. V A-B 9-10)
This sociation was observed exclusively at Nauthagi in Gnúp-
verjaafréttur at an altitude of 600 metres ahove sea level. It is
believed to he rare, and it occurs only in highland areas. The spe-
cies are quite numerous, and the sociation is rather variable, parti-
cularly the frequency of C, rariflora. In some places the hybrid
C. Lyngbyei x C. Bigelowii is very conspicuous, and it is not every-
"vvhere easily distinguishable from C. Lyngbyei. Among other com-
mon species Calamagrostis neglecta, Eriophorum angustifolium and
Polygonum viviparum may he mentioned, all of which may also
be regarded as constant species here.
Ch% is high, as is to he expected, because of Salix glauca. The
analyses are made in close connection with the analysis of E. angus-
tifolium — C. rariflora sociation 6 (Tab. 11, 14-16) where the
topography is described.
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