ITALIC 7.0

Chrysothrix caesia (Flot.) Ertz & Tehler

Fungal Divers., 49: 53, 2011. Basionym: Coniangium caesium Flot. in Körb. - Syst. Lich. Germ.: 295, 1855.

Synonyms: Allarthonia caesia (Flot.) Zahlbr.; Arthonia caesia (Flot.) Körb.

Distribution: N - Frl.

Description: Thallus crustose-subleprose, thinly episubstratic, yellowish green to greyish-green, sometimes with a bluish hue, entrely powdery-granulose, poorly delimited, usually without a distinct prothallus, covered with very thin, acicular crystals in herbarium specimens. Apothecia rather rare, without a proper margin, more or less round, 0.2-0.4(-0.7) mm across, at first immersed in the thallus, with a dark brown to black, but densely bluish-grey pruinose, flat to slightly convex disc. Proper exciple poorly developed, very thin, reddish brown; epithecium reddish brown c. 10 μm high; hymenium colourless to yellowish brown, 60-75 μm high; paraphysoids rather thin, sparingly branched and anastomosing, not or only slightly thickened at apex; hypothecium dark red-brown, conical, up to 60 μm high. Asci 8-spored, broadly clavate to subglobose. Ascospores 3-septate, slightly constricte in the middle, more or less bacilliform, 15-22(-24) x 4-6 μm. Photobiont chlorococcoid. Spot tests: thallus K- or K+ pale yellow, C-, KC- or KC+ pale yellow, P-, UV-. Chemistry: usnic acid in thallus, perhaps also zeorin.

Note: a mild-temperate species also known from North America, found on the smooth bark of deciduous trees, especially Carpinus; often sterile and overlooked, being easily confused with species of Lepraria.

Growth form: Crustose

Substrata: bark

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

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: 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:

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6

(info)

Predictive model