ITALIC 8.0

Thelidium abstractum Lettau

Feddes Repert., Beih. 119, 2: 57, 1940.

Synonyms:

Distribution:

Description: Thallus crustose, thinly episubstratic, yellowish-grey, rimose. Perithecia black, 0.2-0.3(-0.4) mm across, projecting from the rock, not covered by thallus. Involucrellum well-developed, brown-black, surrounding the ostiolar region; exciple thin, paraplectenchymatous, colourless to olive-green, dark olive-brown in the periostiolar region; hamathecium of periphyses and periphysoids, interascal filaments absent. Asci 8-spored, narrowly ellipsoid to clavate, I-, fissitunicate, the wall thickened above, with an ocular chamber, dehiscent by extrusion of a delicate rostrum. Ascospores 1-septate, hyaline, ellipsoid, 25-37 x 10-15 µm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: unknown, probably without lichen substances.

Note: a very poorly known species of the T. pyrenophorum-group, mainly characterized by the smaller perithecia, found Flysch and calciferous schists in the alpine belt, so far recorded from a few localities in the Alps (Austria, Switzerland). To be looked for in the Italian Alps.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Poorly known taxon in need of further study

pH of the substrata:

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Solar irradiation:

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Aridity:

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model