Thelomma siliceum (Fée) Tibell

Bot. Not., 129: 243, 1976. Basionym: Gassicurtia silicea Fée in Mérat - Nouv. Fl. Envir. Paris: 252, 1831.
Synonyms: Carlosia lusitanica Samp.; Coniothecium siliceum (Fée) Keissl.; Spilomium siliceum (Fée) Nyl.
Distribution: C - Tosc (Puntillo & Puntillo 2009), Sar (Nöske 2000, Puntillo & Puntillo 2009).
Description: Thallus crustose, episubstratic, verrucose–areolate, sometimes sublobulate at margins, greenish grey to grey. Areoles 0.8-1.2 mm wide, granulose, the fertile ones verrucose. Cortex 30-50 μm thick, inspersed with coarse granular crystals; medulla thin, white, I-. Apothecia immersed in the warts, 0.6–0.8(-1) mm across, round to irregular in outline by mutual compression, with a black mazaediate disc, and a more or less crenulate, whitish thalline margin. Exciple very thin, raised; hymenium 70-110 µm high; hypothecium dark brown, 160-220 μm high. Asci cylindrical, formed singly and dissolving early, with 1-seriately arranged spores. Ascospores 1-celled, brown, globose, 10-14 μm wide, with an irregular ornamentation visible under the optical microscope. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC+ pink to red, P–. Chemistry: mazaedium with norstictic and salazinic acids; thallus with orcinol depsides and depsidones.
Note: on hard siliceous rocks in open sites exposed to humid, maritime winds in the Mediterranean belt; certainly very rare, and probably restricted to Tyrrhenian Italy.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: absent
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: absent
Humid mediterranean belt: extremely rare
Dry mediterranean belt: absent

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
Herbarium samples


P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (10197)
2001/12/03
detail of apothecia



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (10197)
2001/12/03



P.L. Nimis CC BY-SA 04
TSB 10197


Pier Luigi Nimis - CC BY-SA 4.0
Herbarium: TSB 10197



Domenico Puntillo - CC BY-SA 4.0
Italy



Domenico Puntillo; Owner: Domenico Puntillo
Italy