Bacidia polychroa (Th. Fr.) Körb.

Parerga Lichenol.: 131, 1860. Basionym: Biatora polychroa Th. Fr. - Öfvers. K. Svensk. Vetensk.-Akad. Förh., 12, 1: 17, 1855.
Synonyms: Bacidia acerina (Ach.) Arnold non auct.; Bacidia fuscorubella (Hoffm.) Bausch; Bacidia polysita (Stirt.) A.L. Sm.; Lecidea acerina (Ach.) Röhl.; Lecidea luteola var. fuscorubella (Hoffm.) Ach.; Secoliga fuscorubella (Hoffm.) Stizenb.; Verrucaria fuscorubella Hoffm. nom. inval.
Distribution: N - TAA (Nascimbene & al. 2007b, Nimis & al. 2015), Lomb, Emil (Fariselli & al. 2020). C - Mol (Paoli & al. 2015). S - Camp (Nimis & Tretiach 2004).
Description: Thallus crustose, episubstratic, continuous, rimose or finely warted-areolate, whitish to grey or yeIlowish grey. Apothecia lecideine, (0.4-)0.6-0.8(-1.2) mm across, brown-orange to purplish brown, often darkening with age, with a flat to finally convex, epruinose or white-pruinose disc, and a concolorous or slightly darker, at first thick and raised, finally excluded proper margin. Proper exciple 45-95 μm wide laterally, without crystals or with radiating clusters of minutc crystals, pale yellowish brown, orange-brown to dark brown, K+ purple-red in outer and upper parts, often slightly paler within and colourless in lower parts; epithecium pale brown, scarcely differentiated from the hymenium; hymenium (56-)63-94(-100) μm high, colourless or very pale brown-orange in lower part, the upper part concolorous or (rarely) deep brown-orange; paraphyses 1-1.6 μm thick at mid-level, the apical cells not thickened or up to 3 μm wide; hypothecium brown-orange to dark brown, darker than exciple. Asci 8-spored, cylindrical-clavate, surrounded by a gelatinous I+ blue coat, with a well-developed I+ blue tholus, a I+ darker blue tube and a well-developed ocular chamber, Bacidia-type. Ascospores (3-)7-15-septate, hyaline, acicular, straight to sigmoid, (38-)43-57(-74) x (2-)3-4(-5) μm. Pycnidia immersed, pale brown around the ostiole. Conidia simple, filiform, curved, 10-17 x 0.6-0.8 μm. Photobiont chlorococcoid, the cells 5-12 μm in diam. Spot tests: thallus K-, C-, KC-, P-, UV-; pigmented parts of apothecia K+ purple-violet, N-. Chemistry: thallus without lichen substances or with traces of atranorin; apothecia with the Bacidia-brown and Rubella-orange pigments.
Note: a mild-temperate to tropical species found on broad-leaved trees in open, humid forests. It is included in the Italian red list of epiphytic lichens as “Endangered” (Nascimbene & al. 2013c).
Growth form: Crustose
Substrata: bark
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: extremely rare
Padanian area: absent
Humid submediterranean belt: extremely rare
Humid mediterranean belt: extremely rare
Dry mediterranean belt: absent


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)

1

2

3

4

5





E. Pittao CC BY-SA 4.0
TSB 28616



Felix Schumm - CC BY-SA 4.0
[20555], U.S.A., Minnesota, Mahnomen County, East of Washington Lake (18 miles NE of Mahnomen). In swamp area with balsam fir, spruce, tamarack, on ash. Leg. C. M. Wetmore (26401), 11.8.1976.



Felix Schumm - CC BY-SA 4.0
[20569], U.R.S.S., Transcaucasus, Colchis; distr. Sochi, in monte Achun, 600-650 m. Ad corticem Sorbi torminalis. Leg. A. Vezda, 17.06.1979.



Felix Schumm - CC BY-SA 4.0
[20569], U.R.S.S., Transcaucasus, Colchis; distr. Sochi, in monte Achun, 600-650 m. Ad corticem Sorbi torminalis. Leg. A. Vezda, 17.06.1979.



Felix Schumm - CC BY-SA 4.0
[20569], U.R.S.S., Transcaucasus, Colchis; distr. Sochi, in monte Achun, 600-650 m. Ad corticem Sorbi torminalis. Leg. A. Vezda, 17.06.1979.



Pier Luigi Nimis CC BY-SA 4.0
TSB 41675



Felix Schumm - CC BY-SA 4.0
[20555], U.S.A., Minnesota, Mahnomen County, East of Washington Lake (18 miles NE of Mahnomen). In swamp area with balsam fir, spruce, tamarack, on ash. Leg. C. M. Wetmore (26401), 11.8.1976.