Placynthiella dasaea (Stirt.) Tønsberg

Sommerfeltia 14: 271, 1992. Basionym: Lecidea dasaea Stirt. - Scottish Natur., 5: 219, 1880.
Synonyms:
Distribution: N - Ven (Thor & Nascimbene 2007), TAA (UPS-L-166869), Lomb (UPS-L-166868).
Description: Thallus crustose, episubstratic, consisting of minutely coralloid goniocysts, pale to dark brown or greenish brown, continuous, cracked or indistinctly areolate, sorediate, forming rounded to irregular patches usually up to a few cm across, occasionally to 10 cm or more, without a distinct prothallus. Areoles usually absent, or formed in very young thalli, irregularly rounded, flattened to convex, up to 0.2 mm in diam. Soralia brown due to pigmentation of the external soredia, or greenish in abraded parts, mostly discrete, at first rounded and convex, later confluent into a subleprose, thick, often cracked crust. Soredia mostly farinose, 20-30 μm in diam., sometimes gathered into up to 45(-65) μm wide consoredia. Apothecia very rare, biatorine, up to 0.3 mm across, with a brown disc and a slightly paler, thin proper margin. Proper exciple brown, pseudoparenchymatous; epithecium brown, C+ red; hymenium colourless or very pale brown, I+ reddish brown; paraphyses strongly coherent, sparingly branched and anastomosing, the apical cells swollen, with a dark cap; hypothecium brown. Asci 8-spored, cylindrical-clavate, thin-walled, the apical dome mostly I-, Trapelia-type. Ascospores 1-celled, hyaline, ellipsoid, 9-11 x 4-5 μm. Photobiont chlorococcoid. Spot tests: thallus K-, C+ red, KC+ red, P- (reactions best seen in squash preparations), UV- or UV+ faintly whitish blue in poorly pigmented specimens. Chemistry: gyrophoric acid (major), lecanoric acid (traces).
Note: on acid soil, lignum and bark in upland areas; probably more widespread in the Alps, but overlooked.
Growth form: Crustose
Substrata: lignum, soil, terricolous mosses, and plant debris
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)
Pioneer species

Commonnes-rarity: (info)

Alpine belt: rather rare
Subalpine belt: rather common
Oromediterranean belt: very rare
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:

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Solar irradiation:

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Aridity:

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model

Leif Stridvall - Source: http://www.stridvall.se/la/galleries.php


Leif Stridvall - Source: http://www.stridvall.se/la/galleries.php


Author: Leif Stridvall - Source: http://www.stridvall.se/la/galleries.php