A Synopsis of the Genera Skyttea, Llimoniella and - Lichens of ...

450 THE LICHENOLOGIST Vol. 32
For a description and illustrations, see Hawksworth (1982).
Host. Probably on the thallus of Micarea denigrata.
Distribution. Great Britain (Scotland), known only from the type locality.
Observations. This species is characterized by the very short and narrow
ascospores and the large ascomata.
Llimoniella Hafellner & Nav.-Ros.
Herzogia 9: 770 (1993); type: Llimoniella scabridula (Mull. Arg.) Nav.-Ros. & Hafellner.
Ascomata lichenicolous, commensalistic, black, sessile to shortly pedicellate,
marginate, disc plane, slightly concave or becoming convex. Exciple formed of
dark, thick-walled, catenate, ± isodiametric cells, the outer cells being often
enlarged or swollen (best observed in commercial bleach), without hairs or
periphysoids, reddish to purplish brown (see Fig. 7). Subhymenium hyaline.
Hymenium hyaline, KI — . Epihymenium purplish. Pigments: (1) reddish to
purplish brown, K+ violaceous, N - or greyish brown, in the exciple and
epihymenium; (2) pale olivaceous, usually hidden by the darker purplish
pigment, K+ bright green, N — , in the exciple and the hymenium [pigment
absent in L. adnata and L. scabridula]; (3) yellowish or orange, K —, N+
bright orange, in the excipular and epihymenial gel. Paraphyses simple or
apically branched, apically indistinctly swollen, without pigments, easily
separating in KOH under slight pressure. Asci clavate, thin-walled, wall
apically hardly thickened, KI — , normally 8-spored. Ascospores hyaline, 0-3septate,
smooth, without a perispore, ellipsoid, fusiform, cylindrical or sigmoid,
1-2- or multiguttulate. Conidiomata known in one single species (L.
vinosa), pycnidial, globose, erumpent, wall reddish brown, apically greenish
brown. Conidiogenous cells phialidic, hyaline. Conidia bacilliform, hyaline.
Observations. The genus Llimoniella was originally introduced for two closely
related species, L. adnata and L. scabridula. Subsequent authors added
a number of related, but not congeneric species: Llimoniella fuscoatrae,
L. neglecta, L. pubescens and L. stereocaulorum belong to Rhymbocarpus, and
L. groenlandiae neither belongs to Rhymbocarpus nor to Llimoniella, but
to Unguiculariopsis (see under 'Excluded species')-
Llimoniella is characterized by blackish, superficial apothecia with a ±
regular, smooth, striate or scabrous margin lacking hairs and a slightly concave
to convex disc; an upper exciple composed of radiating, thick, catenate cells;
the combination of very characteristic pigments; thin-walled asci without any
hemi-amyloid reactions; and ellipsoid or elongate, straight or curved to
sigmoid, 0-3-septate, 1-2- or multiguttulate, hyaline ascospores lacking a
distinct perispore. For differences with Rhymbocarpus, see the identification
key to lichenicolous leotialean fungi below.
Llimoniella pertusariae is the only species of the genus in which we have seen
living ascospores. They are multiguttulate, containing hundreds of minuscule