The Botany of Iceland - 01.12.1912, Síða 176

162
H.JÓNSSON
If we now turn to the individual species which (besides those
already mentioned) are found in the one coastal district but are
absent from the other, and which are important as regards Ihe
appearance of the vegetation, we see, as already mentioned, that
such species are few in E. Iceland and numerous in S. Iceland.
Some of these species have a fairly social growth without, however,
forming independent associations. In the following, only those
species are given which occur most abundantly.
South Iceland.
Lomentaria clavellosa.
Plocamium coccineunt.
Chantransia Alariæ.
Callithamnion Arbuscula.
Plumaria elegans.
Ceramium acanthonotum.
C. rubrum.
Polysiphonia fastigiata.
Rhododermis parasitica.
Cystoclonium purpurascens.
Ptilota plumosa.
Petrocelis Hennedvi.
Ectocarpus fasciculatus.
E. tomentosus.
Cladophora rupestris.
Enteromorpha Linza.
It should moreover be noted that all the Cera/nífinJ-species are
absent from E. Iceland. In S. Iceland, besides those mentioned
above, Ceramium atlaniicum occurs, and it will no doubt be possible
to find several more Ceramium-species in S. Iceland.
The Epiphytic Vegetation on Laminaria hyperborea, as
mentioned several times, is very luxuriant in S. aud SW. Iceland;
in NW. and N. Iceland it must also be said to be fairly luxuriant,
hut in E. Iceland it is quite iníinitesinial in ainount, wliich is pro-
bably connected with the fact that Laminaria hyperborea is rare in
E. Iceland.
The epiphytic vegetation on the stipes ol' Laminaria hyperborea
is very luxuriant and fmely developed in S. Iceland. The following
from the Vestmannaeyjar are given as an example: — dominantly
on the stipe of L. hyperborea occurred Rhodymenia palmata, Delesseria
alata and Plocamium coccineum; less abundantly than the three
above-mentioned species occurred Delesseria sanguinea, Lomentaria
clavellosa, Lomentaria rosea, Euthora cristata, Gigartina mamillosa,
Ahnfeltia plicata, Petrocelis Hennedyi, Dermatolithon macrocarpum and
East Iceland.
Lithothamnion flavescens.
L. foecundum.
Laminaria nigripes.
Turnerella Pennyi.
Ptilota pectinata.
Peyssonellia Rosenvingii.
Coilodesme bulligera.
Ulothrix consociata var. islandica.