(2009): Lichens in Scandinavia known mainly from Norwegian type ...

GRAPHIS SCRIPTA 21 (2009) Lichens mainly known from Norwegian types 2
theca hygrophila, Erioderma pedicellatum and
Szcawinskia leucopoda.
Norway surprisingly also has the driest,
most continental regions in Fennoscandia,
those of the inner, dry valleys of Opland and
adjacent counties, in the rain shadow of
Jotunheimen (Ahlner 1949, Kleiven 1959),
which contain xerophilous steppe-elements, not
found elsewhere in our region, e.g. Buellia
asterella, Caloplaca tominii, Fulgensia
desertorum, Gyalidea asteriscus, Phaeorrhiza
sareptana, Rinodina terrestris, Squamarina
magnussonii, Toninia sculpturata and T.
taurica.
Norway reaches further north than any other
of the Fennoscandian countries and has the
highest mountains. This is reflected in arcticalpine
species, such as Arctocetraria andrejevii,
Asahinea chrysantha, Buellia adjuncta, Lobothallia
alphoplaca and Rhizocarpon dinothetes.
Finally there remains a residue of rare
species which does not necessarily fall into
these categories. They are all described from
Norway and have remained known only, or
mainly, from the type-collections. They
therefore need particular attention, requiring
reexamination, preferably on freshly collected
material to ascertain their taxonomic and
conservation status. There are two possible
main reasons for their rarity:
1. They are parts of poorly understood species
complexes in difficult, not fully understood
genera.
2. They are genuinely rare or overlooked.
From a conservation point of view it is
important to single out the truly rare species
with their only Scandinavian occurrence in
Norway, and to see if they represent phytogeographical
elements to which also other rare
lichens belong.
We are not in a position to resolve the
matter fully as we have been unable to secure
the necessary new material for study, but we
have prepared a commented list on them,
hopefully inspiring other colleagues to make an
attempt to resolve the remaining problems,
which are long overdue.
We have as far as possible studied the type
specimens microscopically and chemically
(TLC). However, some types are so minute that
we have not dared to take more bits,
particularly if studies of spores or chemistry
would not be taxonomically important.
List of species
Acarospora impressula Th.Fr.
Type: Norway, Akershus, Lindøya, 1869, N.G.
Moe (UPS!, lectotype, here selected, Fig. 1).
TLC: no substancees detected.
This is a rather nondescript species in the
Acarospora badiofusca group. Magnusson
(1929) points out the dark, continuous, areolate
crust with a negative C-reaction, the immersed
apothecia, and the broadly ellipsoid spores. The
collector of the original material has noted that
it grew only on dry rocks warmed by the
afternoon sun, which is an indication that it is
one of the southern thermophilous elements,
restricted to the Oslofjord-region (e.g. Anema)
or also present in SE Sweden. This might
account for its rarity, but the world distribution
of this species does not confirm this. In Central
Europe it is recorded as a high montane species
Figure 1. Acarospora impressula, part of
lectotype. Bar = 1 mm.