Biatora subgilva (Arnold) Hinter.

Bibl. Lichenol., 55: 112, 1994. Basionym: Biatora vernalis var. subgilva Arnold - Verh. K. K. zool.-bot. Ges. Wien, 46: 141, 1896.
Synonyms: Biatora vernalis f. subgilva (Arnold) Arnold; Lecidea vernalis f. subgilva (Arnold) Zahlbr.
Distribution: N - Frl.
Description: Thallus crustose, episubstratic, grey-brown to green-brown, coarsely granular to warted, sometimes partially rimose, consisting of 0.15-0.5 mm wide areoles, or reduced to a few granules around the apothecia. Medulla white, I+ pale blue. Apothecia biatorine, 0.2-0.4 mm across, rounded to irregular in outline, isolated or clustered, broadly adnate, with a pale ochre to orange-brown, sometimes faintly pruinose, convex disc, and a paler, thin, soon excluded proper margin. Proper exciple poorly developed, colourless to pale yellow, of radiating hyphae, the outer part I+ blue or pale violet, inspersed with numerous small crystals soluble in K but not in N, usually arranged in thin vertical lines; epithecium orange-brown to brown, with a finely granulose epipsamma, c. 10 μm high; hymenium colourless to pale brown, 40-60 μm high, I+ blue turning red-brown; paraphyses branched, the apical cells not or only slightly swollen, 2-3.5 μm wide; hypothecium colourless, usually without crystals, 50-80 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. Ascospores 1-celled (rarely 1-septate), hyaline, narrowly ellipsoid to irregular in outline (often tapering at one end), of very different sizes, 9-20(-37) x 2.5-3.5(-5) μm. Photobiont chlorococcoid. Spot tests: thallus K- or K+ yellowish, C+ pale yellow, KC+ pale yellow, P-. Chemistry: thallus with usnic and isousnic acids.
Note: on old, decaying branches and stems of Rhododendron in siliceous areas of the subalpine belt; most of the records of this very rare, little-known, but well-distinguished species are from Austria, but near the Italian border (see Printzen 1995).
Growth form: Crustose
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: very rare
Oromediterranean belt: absent
Montane belt: absent
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: absent
Humid mediterranean belt: absent
Dry mediterranean belt: absent


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