Variospora flavescens
Variospora flavescens | ||||||||||||
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![]() Caloplaca flavescens (Variospora flavescens) on a limestone rock in Northern Bavaria |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Variospora flavescens | ||||||||||||
( Huds. ) Arup , Frödén & Søchting |
Variospora flavescens (also Hepps Schönfleck ) is an epilithic lichen species fromthe Teloschistaceae family that iscommon in central European limestone areas.
description
Variospora flavescens is a crusty lichen, so its bed ( thallus ) lies close to the base. The rosette-shaped thallus is light yellow to orange in color, sometimes frosted and reaches a diameter of more than 10 cm, whereby the center can be eroded whitish. The marginal lobes are usually convex. The cortex has a continuous layer of hyaline crystals. The apothecia , which occurs particularly frequently in the center of the thallus, reach a diameter of up to 1.5 mm, their edge is lager-colored, while the discs are darker (yellow-orange to orange-brown). The two-celled ascospores are lemon-shaped and measure 12–15 × 8–10 μm.
Thallus and apothecia respond positively to potassium hydroxide (K +), i.e. that is, they turn purple when drizzled.
Variospora flavescens can easily be confused with other species, such as Caloplaca aurantia (whose marginal lobes, however, lie flat, and there is no crystalline layer in the cortex).
distribution
The species occurs on limestone rocks that are slightly to full sunshine or other basic rock, also on anthropogenic substrates such as cement, mortar or roof tiles. It is widespread in Europe, the bordering parts of Asia, Africa and Macaronesia . The focus in Central Europe is on the limestone regions (Limestone Alps, Swabian and Franconian Alb). In Germany it is generally not considered to be endangered, but it is less common in the northern federal states and is listed there with different degrees of risk in the Red Lists .
Systematics
The basionym of the species is Lichen flavescens , there is also a large number of synonyms such as Caloplaca heppiana (in honor of Ernst Hepp , from which the German name is derived), Caloplaca aurantia var. Heppiana or Caloplaca flavescens .
In the course of an extensive phylogenetic investigation of the Teloschistaceae family, including markers from the rRNA , the extensive and heterogeneous genus Caloplaca was split up in 2013 , whereby the species was now assigned to the genus Variospora .
Others
The bryological-lichenological working group for Central Europe named the species as lichen of the year 2017, because it represents a representative of the limestone communities that are threatened in Central Europe outside the Alps.
Individual proof
- ↑ Ulf Arup, Ulrik Søchting, Patrik Frödén: A new taxonomy of the family Teloschistaceae . Nordic Journal of Botany 31 (1), pp. 16-83, pdf