Athallia cerinelloides
Athallia cerinelloides is a species of lichen-forming fungus in the family Teloschistaceae. It grows on bark and produces tiny yellow to orange apothecia, while the thallus is often so reduced that it can be hard to see. The species was long treated in the genus Caloplaca as Caloplaca cerinelloides.
Taxonomy
The species was originally described by the German lichenologist Christian Erichsen in 1930 as Caloplaca pyracea var. cerinelloides. Josef Poelt promoted it to full species status in 1993, as Caloplaca cerinelloides. In 2013, Ulf Arup and colleagues reclassified it in Athallia. The type specimen was collected in 1924 by Erichsen on elder between the villages of Tarp and Süder Schmedeby in Schleswig-Holstein, northern Germany; a lectotype was selected from this material by Arup in 2009 and is housed in the Hamburg herbarium. It belongs to a set of teloschistaceous lichens with a strongly reduced thallus and brightly pigmented apothecia; in this group the apothecial margin is typically, and the spores are .
Description
The thallus is inconspicuous and may be partly, sometimes appearing only as a very thin film close to the apothecia. The apothecia are small, usually about 0.2–0.4 mm across, with yellow to orange. Ascospores are ellipsoid and polarilocular, typically about 10–15 × 6–9 μm, with a relatively thick septum ; pycnidia have not been reported for this species in the material examined.
Habitat and distribution
Athallia cerinelloides occurs on nitrophilous bark across Europe, and it is often found growing alongside the similar bark-dwelling species Caloplaca pyracea.