Cresponea quinqueseptata Aptroot & M. Cáceres, 2021

Aptroot, André, A, Lidiane, Santos, lves dos, E, Marcela, S, ugenia da & Cáceres, ilva, 2021, Saxicolous lichens in the semi-arid Caatinga in Brazil show substratum shifts, Cryptogamie, Mycologie 20 (11), pp. 181-189 : 183

Cresponea quinqueseptata Aptroot & M. Cáceres , sp. nov.

( Fig. 1C, D )

Saxicolous Cresponea with apothecia yellow pruinose, ascospores broadly fusiform, consistently (4-)5-septate, 30-37 × 5-7 Μm.

MYCOBANK NO. — MB 839714.

TYPE. — Brazil, Sergipe, Poço Redondo, Cajueiros , Trilha Ecoparque , 09°39’43”S, 43°40’18”W, on exposed granite, 15.XI.2018, M. Cáceres & A. Aptroot (holo-, ISE [ ISE48046 ]; iso-, ABL).

DESCRIPTION

Thallus

Endolithic, up to 3 mm immersed into the rock in between rock crystals, not visible from above, extending in fissures between rock granules, only visible when rock fragments are removed, with trentepohlioid algae.

Apothecia

Sessile, rather evenly dispersed to crowded, angular to somewhat sinuous in outline, 0.5-2.0 mm diam.; disc black, thinly yellow pruinose; margin higher than the disc, shiny, black, crenulate to fissured, c. 0.2 mm wide.

Epihymenium

Dark brown, c. 30 Μm high, with superficial yellow crystals.

Hymenium

Hyaline to somewhat greyish brown, c. 150 Μm high, filaments anastomosing. Hymenium and excipulum black and continuous, c. 100 Μm thick.

Asci

Cylindrical, c. 70-75 × 13-16 Μm, wall c. 2-3 Μm thick, with small apical chamber.

Ascospores

8/ascus, hyaline, broadly fusiform, consistently (4-)5-septate, 30-37 × 5-7 Μm, constricted at some septa, ends rounded, wall c. 0.5 Μm thick.

Pycnidia

Not observed.

CHEMISTRY. — Apothecia disc pigment KOH+ yellow exuding (no TLC performed).

ECOLOGY AND DISTRIBUTION. — On exposed granite in Caatinga. Known only from Brazil.

Figures

FIG. 1. — A, B, Leprocollema nova-caledoniarum A.L. Sm., ISE 48008: A, habitus (all the brownish black), with a turtle; B, detail with apothecium. C, D, Cresponea quinqueseptata Aptroot & M. Cáceres, sp. nov., holotype: C, apothecia (note that the thallus is immersed in the rock); D, ascospore. Scale: B, 0.5 mm; C, 2 mm; D, 20 µm.