Usnea glabrescens (Vain.) Räsänen
Vain. ex Räsänen, Luonnon Ystävä, 23: 9, 1919. Basionym: Usnea barbata var. glabrescens Nyl. ex Vain. - Meddeland. Soc. Fauna Fl. Fenn., 2: 46, 1878.
Synonyms: Usnea distincta Motyka nom. illegit.; Usnea extensa Vain.; Usnea glabrella (Motyka) Räsänen
Description: Thallus fruticose-filamentous, greenish, shrubby to subpendulous, stiff, up to 15(-25) cm long, branching mainly isotomic-dichotomously with divergent branches. Main branches cylindrical, tapering, without foveoles or transversal furrows, 0.7-1.2 mm thick, with numerous ramifications only close to the basal part and generally few ramifications in the distal parts, the base black, with distinct annular cracks and often with tiny, lenticular, longitudinally oriented cracks visible at high magnification. Lateral branches not constricted at attachment point, with thick apices. Papillae sparse and almost inapparent to numerous and verrucose; true tubercles absent; fibrils sparse and irregularly dispersed to numerous and with a fish-bone arrangement, slender, 3-7 mm long. Soralia mainly on secondary and terminal branches, bursting from low pustules (tubercle-like structures, but wider than high), at first punctiform, later becoming conspicuous, usually remaining circular and discrete, plane or concave, those of the terminal branches often deeply excavate and reaching the central axis, occupying more than half the diameter of the branch, originating from cortex; isidiomorphs rarely present in young soralia, up to 0.1 mm long. Cortex thick (8-13% of total branch thickness), matt in longitudinal section; medulla white, homogeneous, loose to compact, thin (15-23%); central axis white, rather thick (31-52%); ratio axis/medulla ranging between 1.2 and 5. Apothecia not observed in Italian material. Photobiont chlorococcoid. Spot tests and chemistry: cortex with usnic acid, K-, C-, P-; medulla with different chemotypes: 1) with norstictic and salazinic acids (K+ yellow turning red, P+ yellow to orange) as main compounds plus substances of the stictic acid complex and protocetraric acid (accessory), the most common chemotype in Italy; 2) with norstictic acid as main substance (K+ yellow turning red, P+ orange) plus substances of the stictic acid complex (accessories); 3) with psoromic acid (K- or K+ slowly yellowish, P+ deep yellow) and other accessory substances; 4) without medullary substances (K-, P-). Note: on bark and lignum in cold-humid but open situations in montane to subalpine forests.
Growth form: Fruticose filamentous
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)
Poorly known taxon in need of further study
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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Occurrence data
Predictive map
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32772)
2007/04/25
Rounded and discrete soralia of U. glabrescens
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32777)
2005/09/08
Shrubby thallus
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32776)
2005/09/08
Subpendent thallus
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32772)
2007/04/25
Branches of U. glabrescens
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Leif Stridvall - Source: http://www.stridvall.se/la/galleries.php
Growth form: Fruticose filamentous
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)
Poorly known taxon in need of further study
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
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32772)
2007/04/25
Rounded and discrete soralia of U. glabrescens
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32777)
2005/09/08
Shrubby thallus
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32776)
2005/09/08
Subpendent thallus
Tiiu Tõrra; Owner: University of Tartu
Estonia.
Herbarium: TU (32772)
2007/04/25
Branches of U. glabrescens
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
Tiiu Tõrra; Owner: Tiiu Tõrra - Institute of Ecology and Earth Sciences, University of Tartu, Estonia
