Iodomarcelleina obscura Sammut & Alvarado & Vooren 2023, sp. nov.
Creators: name: Sammut, Carmel
name: Alvarado, Pablo
name: Vooren, Nicolas Van
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Pezizomycetes
Pezizales
Pezizaceae
Iodomarcelleina
Iodomarcelleina obscura

description: Iodomarcelleina obscura sp. nov.
(Figs 3; 4)
Differs from Marcelleina benkertii by the straight and inflated paraphyses and the amyloid reaction of the asci, from the other Marcelleina species by the amyloid reaction of the asci and lack of violaceous tinges in the apothecia, and from Scotopezia pseudoanthracina (Donadini) Van Vooren, Sammut & P.Alvarado, comb. nov. by its smooth ascospores.
HOLOTYPE. — Malta. Mellieha, Ahrax, 35°58’57.0”N, 14°21’43.3”E, 30 m a.s.l., on soil, in an open ground near Pinus halepensis Mill., 3.II.2017, leg. C. Sammut, NV 2022.08.00 (holo-, LY).
ADDITIONAL SPECIMEN EXAMINED. — Malta. Mellieha, Selmun area, 35°57’58.0”N, 14°22’35.0”E, 92 m a.s.l., in a sheltered area on calcareous soil, near Asparagus aphyllus L., Ferula melitensis Brullo, C.Brullo, Cambria, Giusso, Salmeri & Bacch., Teucrium fruticans L., Thymbra capitata Cav., Uriginea maritima (L.) Baker, 16.II.2017, leg. M. Sammut, C.S.1091.
ETYMOLOGY. — From Latin obscurus, meaning dark.
MYCOBANK NUMBER. — MB 849114.
DESCRIPTION
Macroscopic features (Fig. 3)
Apothecia 4-7 mm diam., sessile, discoid, shallowly patelliform to flattened, hymenium smooth and regular, dark brown to black. Margin not differentiated. Flesh up to 750 µm thick, without latex.
Microscopic features (Fig. 4)
Hymenium 260-340 µm thick, brownish, darker near the edge. Asci cylindrical, 190-250×14-21 µm, 8-spored, operculate, with croziers, weakly bluing in IKI (diffused along wall). Ascospores globose, 9.5-11.9 µm diam., Me=10.8 µm, Q = 0.96-1.05, Qe = 1.00 (N = 50), smooth, thick-walled, containing several small oil bodies. Paraphyses thin, slightly claviform, inflated at the tips up to 6 (-10 µm), straight to curved, occasionally branched, multiseptate, with external agglutinated brown pigment. Subhymenium pale brown, 30-50 µm thick, of textura intricata. Medullary excipulum bi-layered: the upper part 30-60 µm thick, of textura angularis, with cells 11-28 µm wide, thin-walled; the lower part 40-60 µm thick, of textura intricata, with hyphae 2.5-5 µm wide. Ectal excipulum 200-270 µm thick, of textura globulosa / angularis, made up of hyaline cells, 12-50 µm diam., arranged perpendicularly to the surface, becoming brownish in the outermost part. Anchoring hyphae present, hyaline, 4-8 µm in diameter.
HABITAT
The area where the holotype was collected consists of a thin strip of land, about 950 m in length and a mean width of 100 m, on a sloping cliffside facing the sea. The vegetation consists of an anthropized maquis, with Olea europaea L., Pinus halepensis and Eucalyptus sp., transitioning to a typical Mediterranean garigue vegetation inclusive of Thymbra capitata, Erica multiflora L., Euphorbia dendroides L. as well as endemic E. melitensis Parlatore. The soil is calcareous with sparse organic matter. There are no natural water sources, and the availability of water depends on rainfalls or contributions from overnight dew. The area is also well known as a popular camping site resulting in a high degree of human activity, particularly from autumn to spring.
description: Published as part of Sammut, Carmel, Alvarado, Pablo & Vooren, Nicolas Van, 2023, Emendation of Marcelleina Brumm., Korf & Rifai (Ascomycota, Pezizales) and proposal of Iodomarcelleina obscura gen. nov., sp. nov. and Scotopezia pseudoanthracina gen. nov., comb. nov. for the lineages outside it, pp. 159-170 in Cryptogamie, Mycologie 44 (12) on pages 164-166, DOI: 10.5252/cryptogamie-mycologie2023v44a12, http://zenodo.org/record/10454545