Acarospora placodiiformis H. Magn.

Göteb. K. Vetensk. Samh. Handl., Ser. B, Math. Naturv. Skr., 6, 17: 18, 1956.
Synonyms:
Distribution: N - Emil (Nimis & al. 1996, Fariselli & al. 2020).
Description: Thallus crustose-placodioid to subsquamulose, greenish-yellow, but usually densely covered with a thick layer of white, granular pruina, areolate, with radiating marginal lobes, forming patches to 5 cm in diam., often starting the life-cycle on terricolous species of Diploschistes, later autonomous. Areoles convex, contiguous; marginal lobes c. 2 mm broad. Medulla thick, white. Apothecia lecanorine, rounded, semi-immersed in the areoles and not constricted at base, 1-5 mm across, with a slightly concave to flat, dark reddish brown to almost black, somehow shiny, smooth disc, and a thick thalline margin. Epithecium brown; hymenium colourless, 100-120 µm high, I+ blue; paraphyses numerous, coherent, simple to sparsely branched in upper part, 1-1.5 µm thick at base; hypothecium colourless. Asci 50-100-spored, clavate, with a distinct apical dome, I . Ascospores 1-celled, hyaline, subglobose, 4-6 x 4-5 µm. Photobiont chlorococcoid. Spot tests: thallus and medulla K-, C-, KC-, P-, UV-. Chemistry: rhizocarpic acid and an unknown terpenoid.
Note: a xeric subtropical species found on weathered gypsum in open situations, mostly below the montane belt. To be looked for in gypsum outcrops of southern Italy (e.g. in Sicilia).
Growth form: Crustose placodiomorph
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Subcontinental: restricted to areas with a dry-subcontinental climate (e.g. dry Alpine valleys, parts of Mediterranean Italy)
paras Diploschistes

Commonnes-rarity: (info)

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


pH of the substrata:

(info)

1

2

3

4

5

Solar irradiation:

(info)

1

2

3

4

5

Aridity:

(info)

1

2

3

4

5

Eutrophication:

(info)

1

2

3

4

5

Poleotolerance:

(info)

0

1

2

3

Altitudinal distribution:

(info)

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5





Felix Schumm; Owner: CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (20701)
2001/11/22



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (6909)
2001/11/21



Felix Schumm; Owner: CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm; Owner: CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995



Felix Schumm - CC BY-SA 4.0
[TSB 20701], Italia, Emilia-Romagna, Prov. Ravenna, Zattaglia, SW slopes of Monte Mauro, c. 400 m, on gypsum. Leg. P.L. Nimis & M. Tretiach, 13.05.1995