Lecanora fluoroxylina Aptroot & M.F. Souza, 2021

Aptroot, André, Souza, Maria Fernanda & Spielmann, Adriano Afonso, 2021, Two new crustose Cladonia species with strepsilin and other new lichens from the Serra de Maracaju, Mato Grosso do Sul, Brazil, Cryptogamie, Mycologie 20 (8), pp. 137-148 : 143-144

Lecanora fluoroxylina Aptroot & M.F. Souza , sp. nov.

( Fig. 3 )

MYCOBANK. — MB 83948.

DIAGNOSIS. — Lignicolous Lecanora with extensive thallus of usnic acid colour, apothecia with granularly sorediate margins that are higher than the disk.

TYPE. — Brazil. Mato Grosso do Sul, Aquidauana, Camisão, alt. 150 m, 20°28’52”S, 55°36’47”W, on wooden fence post, 27. VI.2020, A.Aptroot & M.F. Souza 81401 (holo-, CGMS; iso-, ABL).

ADDITIONAL MATERIAL STUDIED. — Brazil. Mato Grosso do Sul: Miranda, Salobra, on wooden fence post, 26. VI.2020, A.Aptroot & M.F. Souza 81310a; Campo Grande, UCDB campus, on wooden fence post, 13.III.2020, A.Aptroot & M.F. Souza 80858; Mato Grosso: Cuiaba, Chapada dos Guimarães, on wood, 12-18.IX.2020, M.F. Souza & A.Aptroot 104; Paraná: Antonina, Cacatu, on wood of fence, 17.X.2020, M.F. Souza & A.Aptroot 268 (para-, CGMS). CHEMISTRY. — Thallus and apothecia UV-, C-, P+ yellow-orange, K+ yellow, KC+ yellow. TLC: usnic acid and zeorin.

ETYMOLOGY. — Named after the colour that resembles the fluorescence of lichexanthone, and the occurrence on wood.

ECOLOGY AND DISTRIBUTION. — On wooden poles and fences; so far only known from two states in Brazil, but expected to occur in bordering states and countries.

DESCRIPTION

Thallus crustose, lignicolous, greyish green (usnic acid colour), smooth to granular, sorediate, without prothallus or rarely surrounded by thin black line. Soralia pale greenish, initially punctiform, later usually a bit higher than the thallus but soon confluent and covering most of the thallus, of thallus colour or colour a bit more saturated. Soredia granular, 25-45 µm. Apothecia often present, sessile, round to usually angular, 0.2-0.7 mm diam., up to 0.3 mm high. Margin of thallus colour, granular sorediate, higher than the disk, c. 0.1 mm wide. Disk flat to somewhat convex, pale ochraceous, with greenish (usnic acid) pruina. Epihymenium a dense mass of small usnic acid crystals that extend downward in streaks into the hymenium. Hypothecium hyaline. Excipulum only with small usnic acid crystals. Ascospores and pycnidia not observed.

Figures

FIG. 3. — Lecanora fluoroxylina Aptroot & M.F.Souza,sp.nov., isotype,habitus.Width of picture:30 mm.