Heterodermia adunca Jung & Werner, 2023

Jung, Patrick, Werner, Lina, Briegel-Williams, Laura, Emrich, Dina & Lakatos, Michael, 2023, Roccellinastrum, Cenozosia and Heterodermia: Ecology and phylogeny of fog lichens and their photobionts from the coastal Atacama Desert, MycoKeys 98, pp. 317-348 : 317

Heterodermia adunca Jung & Werner sp. nov.

Fig. 3

Type.

Chile. Atacama Desert , Pan de Azucar National Park (25°59'03"S, 70°36'55"W; 764 m a.s.l.) specimen HBG-025795 (Herbarium Hamburgense, Hamburg, Germany).

Diagnosis.

Recognized by its ‘hairy’ growth of the densely ciliated, thin branches.

Etymology.

The epithet ' Heterodermia adunca ' refers to the curled, hooked tips that the species produces regularly.

Description.

Thallus appears hairy and is attached at various parts by inconspicuous, small whitish to brown rhizines, which are significantly thinner and shorter than the cilia. Cilia are black, emerging from the upper cortex, sometimes branched, up to 5 mm in length. Thread-like lobes that have a rounded appearance created by the curving around of the upper cortex forming a rim, but the threads are clearly made up of upper and lower parts once investigated with a good hand lens. Upper cortex present, smooth, white to pale gray, parts that are closer to the substrate often appear brownish (mature parts). Lower cortex missing, surface appears rough and whitish between the rims. Main lobes are several cm long and often stretch out horizontally from which irregular side branches emerge that are shorter than the main branches. Tips of the branches are often tightly curled under forming short spirals. Pycnidia and apothecia absent. Trebouxioid photobionts are arranged in a continuous layer.

Secondary metabolites.

Atranorin, zeorin. UV-, C-, K+ slightly yellow, KC-, P-.

Distribution and ecology.

The species grows attached to stones or on soil restricted to a small strip on top of the steep coastal ridge with high wind speeds and regular fog events. It has also been observed at Alto Patache (Iquique), near the coast in northern Chile. There it grows on SW-facing slopes between ca. 600-1300 m, on low vegetation or directly on soil, in desert vegetation with increased precipitation by fog. Often appears together with H. follmannii .

Notes.

According to the three-gen phylogenetic reconstruction presented here the species falls within the monophyletic Leucodermia cluster and is separated from H. follmannii . According to the ITS-only phylogeny the species falls in a separated cluster together with H. follmannii , one H. leucomelaena and one H. erinacea ITS sequence. In addition, the species might be confused with Heterodermia circinalis but the latter has broader, more flat lobes, its main distribution in the paramos of South America, above 3000 m, its medulla and cortex are P+ and the lichen contains leucotylin.

Figures

Figure 3. Heterodermia adunca sp. nov. A-C photographs of Heterodermia adunca sp. nov. on fine soil in the National Park Pan de Azucar D thallus fragments with black cilia and whitish ventral thallus parts forming a rim without lower cortex E terminal wrapped thallus part with blackish cilia F, G photographs H detail of thallus cross section with photobiont layer showing the curved upper cortex that forms a rim where the white medulla is without a lower cortex I, J terminal thallus parts with the typical wrapped ends. QR code redirects to 3 D scan of Heterodermia adunca sp. nov. PW: Lichen.