''Fuscidea muskeg'' is a species of crustose lichen in the family

Fuscideaceae Fuscideaceae is a family of fungi in the order Umbilicariales The Umbilicariales are an order of lichenized fungi in the subclass Umbilicariomycetidae, class Lecanoromycetes. It contains five families: Elixiaceae, Fuscideaceae, Ophioparmaceae ...

. Found in Alaska, it was described as a new species in 2020 by Tor Tønsberg and Martina Zahradníková. The type species was collected in the Hoonah-Angoon Census Area of Glacier Bay National Park. Here it was found growing on a branch of the tree '' Pinus contorta'' in

muskeg Muskeg (Ojibwe: mashkiig; cr, maskīk; french: fondrière de mousse, lit. ''moss bog'') is a peat-forming ecosystem found in several northern climates, most commonly in Arctic and boreal areas. Muskeg is approximately synonymous with bog or ...

. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''muskeg'' is an Algonquin word for a blanket bog.

Description

''Fuscidea muskeg'' has a crust-like thallus that grows on bark. It forms rounded patches up to a few centimeters in diameter and 0.5 mm thick. The patches are made of discrete, convex areoles measuring in diameter, with a color ranging from pale greenish to greenish with a yellowish tinge. The areoles eventually burst at the top and form

soralia Soredia are common reproductive structures of lichens. Lichens reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungal hyphae wrapped around cyanobacteria o ...

. The soralia are initially discrete, but aggregate later, and in some instances form a granular layer throughout the thallus surface. The photobiont partner of ''Fuscidea muskeg'' is trebouxioid – a spherical, one-celled

green alga The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as ...

. They measure from 8 to 18

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

in diameter (usually between 11 and 15). The results of standard

lichen spot test A spot test in lichenology is a spot analysis used to help identify lichens. It is performed by placing a drop of a chemical on different parts of the lichen and noting the colour change (or lack thereof) associated with application of the chemical ...

s are thallus PD+ (yellow), and C+ (red). The lichen contains alectorialic acid. '' Fuscidea praeruptorum'' is similar in appearance to ''F. muskeg'' but has somewhat longer ascospores (9.5–12 μm compared to 7–10 μm in ''F. muskeg''), and it grows on rocks rather than on bark.

References

{{Taxonbar, from=Q107687166 Umbilicariales Lichen species Lichens described in 2020 Lichens of Subarctic America Fungi without expected TNC conservation status