ITALIC 8.0

Biatora helvola Hellb.

Körb. ex Hellb., Öfvers. K. Svensk. Vetensk.-Akad. Förh., 24: 271, 1867.

Synonyms: Lecidea vernalis subsp. helvola (Hellb.) Th. Fr.

Distribution: N - Frl, Ven (Nascimbene & Caniglia 2000, 2003c), TAA (Printzen 1995, Nascimbene & al. 2006e, 2007b, 2022, Thor & Nascimbene 2007, Nimis & al. 2015).

Description: Thallus crustose, episubstratic, greenish grey to pale grey, continuous, rimose or warted, the warts weakly convex and irregular in outline, 0.1-0.3 mm wide. Apothecia biatorine, rounded or slightly irregular in outline, sessile with a slightly constricted basis, single and 0.3-0.5 mm across, or coalescing-tuberculate and 0.5-1 mm across, with a beige to pale reddish brown, epruinose, flat to moderately convex disc, and a concolorous or paler, thin, soon excluded proper margin. Proper exciple colourless or yellowish, of radially arranged hyphae, laterally 30-70 µm wide, basally much wider, the outer part often with tiny granules of gyrophoric acid forming a smear between the hyphae; epithecium scarcely differentiated from the hymenium, colourless or pale yellow; hymenium 40-60 µm high, colourless or yellowish, the pigmented parts often arranged in thin longitudinal stripes; paraphyses simple or sparingly branched in upper part, 1-1.5(-2) µm thick at mid-level, the apical cells to 2.5-3 µm wide; hypothecium colourless or pale yellow, 25-110 µm high. Asci 8-spored, clavate, with a K/I+ blue apical dome penetrated by a narrow, K/I- apical cushion surrounded by a narrow, deeply K/I+ blue zone, the wall K/I- but surrounded by an I+ red-brown, K/I+ blue outer layer, the ocular chamber relatively small, Biatora-type, 31-46 x 7-12 µm. Ascospores 1-celled (rarely 1-septate), hyaline, (8.5-)10-14(-17) x 3-5 µm. with a c. 0.5 mm thick perispore. Pycnidia rare, immersed, to 40 µm across, the wall colourless. Conidia bacilliform, 6.5-8 x 0.7-1 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C- or faintly C+ pink, KC- or faintly KC+ pink, P- (positive reactions often fleeting and poorly evident); apothecial sections fleeting C+ pink. Chemistry: gyrophoric acid (major), and traces of lecanoric acid.

Note: a mainly boreal-montane, circumpolar species found on basal parts of trees in open montane to subalpine forests, often with Parmeliopsis hyperopta; certainly more widespread in the Alps.

Growth form: Crustose

Substrata: bark

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: rather common

Oromediterranean belt: absent

Montane belt: rather rare

Submediterranean belt: absent

Padanian area: absent

Humid submediterranean belt: absent

Humid mediterranean belt: absent

Dry mediterranean belt: absent

pH of the substrata:

1

2

3

4

5

(info)

Solar irradiation:

1

2

3

4

5

(info)

Aridity:

1

2

3

4

5

(info)

Eutrophication:

1

2

3

4

5

(info)

Poleotolerance:

0

1

2

3

(info)

Altitudinal distribution:

1

2

3

4

5

6

(info)

Predictive model

Herbarium samples

E. Pittao CC BY-SA 4.0

TSB 29410

E. Pittao; Owner: Department of Life Sciences, University of Trieste

Herbarium: TSB (29410)
2008.03.31

E. Pittao; Owner: Department of Life Sciences, University of Trieste

Herbarium: TSB (29410)
2008.03.31

E. Pittao; Owner: Department of Life Sciences, University of Trieste

Herbarium: TSB (29410)
2008.03.31