Usnea viktoriana P.Clerc & Otte
Lichenologist 50: 514, 2018
Synonyms:
Description: Thallus fruticose-filamentous, greenish, shrubby to subpendulous, up to 15 cm long, anisotomic-dichotomously branching, the basal branches spreading laterally. Main branches cylindrical or slightly swollen, papillose, sometimes short and dividing quickly into secondary branches (thallus shrubby), or remaining clearly visible (thallus subpendulous); segmentation inconspicuous, with 0.6-2 mm thick annulations, the segments cylindrical or slightly swollen, the base blackened on 1-3 mm, usually thinner at the contact point with the bark and then slightly enlarging towards the main branches; lateral branches not constricted at attachment point, with or without fibrils. Foveolae, maculae, tubercles and pseudocyphellae absent; papillae always present on main branches, numerous, short verrucose to subcylindrical, 35-50 x 50-90 μm; fibrils few and scattered to rarely numerous on young branches. Soralia developing on the apices of thin lateral branches, punctiform when young, later forming larger, irregular, nodulose aggregates, usually even with cortex, slightly excavate when isidiomorphs are shed, with numerous isidiomorphs and fragile, often fasciculate, 0.25-0.7 mm long isidiofibrils. Cortex matt, moderately thick (6-13 % of total branch thickness); medulla dense, white, moderately thin to moderately thick (10-30.5 %); central axis white, moderately thin to moderately thick (26-62 %); ratio axis/medulla: (0.8-)1-2.8(-6.2). Apothecia rare, lecanorine, subterminal, up to 5 mm across. Asci 8-spored, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, c. 8 x 5 µm. Photobiont chlorococcoid. Spot tests: cortex K-, C-, P-; soralia K- or K+ reddish orange, C- or C+ red, KC- or KC+ red, P-. Chemistry: cortex with usnic acid; the most common chemotype contains (in the soralia) alectorialic acid and 5,7-dihydroxy-6-methylphthalide (soralia K-, C+ and KC+ red), other chemotypes may contain salazinic (main) and barbatic (accessory) acids, or no lichen substances.
Growth form: Fruticose filamentous
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)
Subcontinental: restricted to areas with a dry-subcontinental climate (e.g. dry Alpine valleys, parts of Mediterranean Italy)
Commonnes-rarity: (info)
Alpine belt: absent
Subalpine belt: rather rare
Montane belt: very rare
Dry submediterranean belt: absent
Humid submediterranean belt: absent
Padanian area: absent
pH of the substrata:
1 2 3 4 5
Solar irradiation:
1 2 3 4 5
Aridity:
1 2 3 4 5
Eutrophication:
1 2 3 4 5
Poleotolerance:
0 1 2 3
Altitudinal distribution:
1 2 3 4 5 6
Rarity
absent
extremely rare
very rare
rare
rather rare
rather common
common
very common
extremely common
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Source: Clerc P., Otte V. 2018. Usnea viktoriana (Ascomycota, Parmeliaceae), a new European taxon of the Usnea barbata-dasopoga group, with a key to the shrubby-subpendulous sorediate Usnea species in Europe. Lichenologist, 50, 5: 513-527.
holotype
Growth form: Fruticose filamentous
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)
Subcontinental: restricted to areas with a dry-subcontinental climate (e.g. dry Alpine valleys, parts of Mediterranean Italy)
Commonnes-rarity: (info)
Alpine belt: absent
Subalpine belt: rather rare
Montane belt: very rare
Dry submediterranean belt: absent
Humid submediterranean belt: absent
Padanian area: absent
pH of the substrata:
| 1 | 2 | 3 | 4 | 5 |
Solar irradiation:
| 1 | 2 | 3 | 4 | 5 |
Aridity:
| 1 | 2 | 3 | 4 | 5 |
Eutrophication:
| 1 | 2 | 3 | 4 | 5 |
Poleotolerance:
| 0 | 1 | 2 | 3 |
Altitudinal distribution:
| 1 | 2 | 3 | 4 | 5 | 6 |
Rarity
absent
extremely rare
very rare
rare
rather rare
rather common
common
very common
extremely common
Loading data...
Occurrence data
Predictive map
