Bacidia arceutina (Ach.) Arnold

Verh. zool.-bot. Ges. Wien, 19: 624, 1869. Basionym: Lecidea luteola var. arceutina Ach. - Meth. Lich.: 61. 1803.
Synonyms: Bacidia arceutina (Ach.) Rehm & Arnold; Bacidia arceutina (Ach.) Th. Fr.; Bacidia coerulea Körb.; Bacidia effusa (Sm.) Trevis. non auct.; Bacidia leightoniana (Larbal. ex Leight.) H. Olivier; Bacidia luteola var. fuscella Mudd; Lecidea arceutina (Ach.) Gray
Distribution: N - Frl, Ven (Nascimbene & al. 2021), TAA (Nascimbene & al. 2007b, 2014, Nascimbene 2014), Lomb, Piem (Isocrono & al. 2004), Lig (Giordani & Incerti 2008). C - Tosc (Brackel 2015), Marc (Nimis & Tretiach 1999, Umb (Ravera 1998, Ravera & al. 2006), Laz (Ravera & al. 2003, Ravera 2006c, Munzi & al. 2007), Abr (Nimis & Tretiach 1999, Caporale & al. 2016), Mol (Ravera & Genovesi 2012, Paoli & al. 2015), Sar (Zedda 2002, 2002b, Zedda & al. 2001, Cossu 2013, Nascimbene & al. 2021). S - Camp (Aprile & al. 2003b, Nimis & Tretiach 2004, Garofalo & al. 2010, Brunialti & al. 2013, Ravera & Brunialti 2013), Pugl (Nimis & Tretiach 1999), Cal (Puntillo 1995, 1996, Puntillo & Puntillo 2004), Si (Nimis & al. 1994, Ottonello 1996, Grillo & Caniglia 2004 Liistro & Cataldo 2011).
Description: Thallus crustose, endosubstratic or thinly episubstratic, white to pale grey, continuous to rimose, rarely minutely granular. Apothecia lecideine, (0.2-)0.5-0.8(-1) mm across, at first yellowish brown, then brown to brown-black, with a flat to finally convex, epruinose disc, and a usually darker, finally sometimes excluded proper margin. Proper exciple brownish in outer part, colourless or pale yellow within, 60-95 μm thick laterally, 100-125 μm thick at base, of radiating hyphae, usually with a single row of up to 6 μm thick, rounded cells along the outer edge, the pigmented parts K- or K+ yellow; epithecium yellow-brown brownish or olive-brown, K-, N-; hymenium colourless, 45-70(-90) μm high, I+ blue, K/I+ deep blue; paraphyses 0.8-1.5 μm thick at mid-level, simple or irregularly forked in upper part, the apical cells up to 2.5(-4) μm wide; hypothecium colourless or yellow-brown and K+ intensifying yellow in upper part, 20-35 μm high. Asci 8-spored, 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-septate, hyaline, acicular. (32-)35-55(-70) x 1.2-2(-2.5) μm. Pycnidia rare, inconspicuous, immersed. Conidia filiform, curved, 9-17 x c. 0.7 μm. Photobiont chlorococcoid, the cells 5-12 μm in diam. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: thallus without lichen substances.
Note: a mild-temperate to humid subtropical species found on bark of broad-leaved trees (especially Acer, Fraxinus and Populus) in open deciduous woodlands near rivers, very rarely calcicolous or muscicolous.
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: extremely rare
Submediterranean belt: very rare
Padanian area: absent
Humid submediterranean belt: rather rare
Humid mediterranean belt: rare
Dry mediterranean belt: absent


pH of the substrata:

(info)

1

2

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4

5

Solar irradiation:

(info)

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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





P.L. Nimis CC BY-SA 04
TSB 14656



E. Pittao; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (TSB 14656)
20.10.2009



Domenico Puntillo; Owner: Domenico Puntillo
Italy


Leif Stridvall - Source: http://www.stridvall.se/la/galleries.php (Courtesy: Anita Stridvall)



E. Pittao; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (TSB 14656)
20.10.2009



Felix Schumm - CC BY-SA 4.0
Image from: F. Schumm (2008) - Flechten Madeiras, der Kanaren und Azoren. Beck, OHG - ISBN: 978-3-00-023700-3



Felix Schumm - CC BY-SA 4.0
Image from: F. Schumm (2008) - Flechten Madeiras, der Kanaren und Azoren. Beck, OHG - ISBN: 978-3-00-023700-3



Felix Schumm - CC BY-SA 4.0
Image from: F. Schumm (2008) - Flechten Madeiras, der Kanaren und Azoren. Beck, OHG - ISBN: 978-3-00-023700-3



Felix Schumm - CC BY-SA 4.0
Image from: F. Schumm (2008) - Flechten Madeiras, der Kanaren und Azoren. Beck, OHG - ISBN: 978-3-00-023700-3



Felix Schumm - CC BY-SA 4.0
Image from: F. Schumm (2008) - Flechten Madeiras, der Kanaren und Azoren. Beck, OHG - ISBN: 978-3-00-023700-3


Leif Stridvall - Source: http://www.stridvall.se/lichens/gallery/
Courtesy: Anita Stridvall


Leif Stridvall - Source: http://www.stridvall.se/lichens/gallery/
Courtesy: Anita Stridvall


Leif Stridvall - Source: http://www.stridvall.se/lichens/gallery/
Courtesy: Anita Stridvall


Leif Stridvall - Source: http://www.stridvall.se/lichens/gallery/
Courtesy: Anita Stridvall



Felix Schumm – CC BY-SA 4.0
Image from: F. Schumm (2008) - Flechten Madeiras, der Kanaren und Azoren. Beck, OHG - ISBN: 978-3-00-023700-3