CRAPHIS ScnIPTA - Universitetet i Oslo

1,4 Per M. Jpryensen and Aino Henssen GRAPHTS SCRTPTA s (1ee3)
Figure 2. World-distribution of ,S.
omphalaioides. Dots: studied material; triangles:
records from literature.
Apothecia numerous up to 1(-1.5) mm diam,
appearing more or less stalked at the top of
the lobules (see Figure 1) with reddish to
blackish brown disc and with a granulose thalline
exciple. Pycnidia immersed, about 0.1 mm
diam. with blackish ostiole.
Anatomy
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Thallus homoiomerous without distinct cortex,
but with concentration of hyphae and algae at
the surfaces, up to 400 pm thick, with Nostoc
in chains, individual cells 4-5 pm diam.
Apothecia with 150-200 pm wide thalline
exciple; proper exciple distinctly paraplectenchymatous,
60-90 pm wide; subhymenium of
compacted, unorientated, gelatinous hyphae,
yellowish, 40-70 pm wide; hymenium to 100
pm high, hyaline or pale yellow, except in
upper parts where it is brown-pigmented, I+
blue in lower parts; paraphyses simple, septate,
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simple, hyaline, rather thick-walled, globular
(7-10,am diam) to oblong (L2-15 x 7-I0 Fm),
surface usually somewhat warted.
Pycnidia with branched, fairly short-celled
conidiophores, producing rod-like conidia, c. 3
x L pm, laterally and terminally.
Variation
S. omphalarioides is not a very variable species,
mostly varying in size, degree of granulosity,
and colour of thallus and apothecial
disc, a variation certainly caused by environmental
factors. The variation in size and form
of the spores reported above, can be found
within one apothecium, and shows no pattern
indicating differences benreen populations.
Possible confusion
As has already been pointed out by Aru:i
(186?), S. omphalaioides can be confused
with Collema fasciculare (L.) G. H. Weber,
which has similarly caespitose thalli with
numerous apothecia produced on ascending
lobes. That species, however, does not produce
such granular, isidia-like structures, has more
undulating lobe-margins, and in any case of
doubt the long, vermiform, multi-septate
spores will always serve to identiff it conclusively.
Clearly these two species represent a
notable example of convergence between rpo
different, though related genera.
Ecology
S. omphalaioides is a mainly corticolous species,
only recorded from soil or mossy rocks
twice (Mies 1989). It appears to prefer coarsebarked
trees, Quercus and Olea being the most
frequently recorded, followed by Castanea.
Degelius (1955) has recorded several other
less important phorophytes to which can be
added Acacia, Cednts, Eucatyptus, Euphorbia
tuckqana and Pinus canariensrs (from the
Cape Verde Is., Mies 1989) and Pistacia (from
Israel). Most of these are acid-barked trees. It