''Sclerococcum toensbergii'' is a species of lichenicolous (

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

in the family

Sclerococcaceae The Dactylosporaceae or Sclerococcaceae are a family of lichen-forming fungi in the class Eurotiomycetes. It is the only family of the order Sclerococcales and subclass Sclerococcomycetidae. Taxonomy There are currently seven genera in the fami ...

. It is known from only a couple of collections made in the northwestern United States, and a collection in France. In the United States, it has been recorded on the bark-dwelling lichens ''

Megalaria pulverea ''Megalaria'' is a genus of lichenized fungi in the family Ramalinaceae. The genus was circumscribed by Austrian lichenologist Josef Hafellner in 1984. Species *'' Megalaria allantoidea'' *'' Megalaria beechingii'' *'' Megalaria bryophila'' *''M ...

'' and '' Pertusaria carneopallida'', while in France, it was found growing on ''

Caloplaca cerina ''Caloplaca'' is a lichen genus comprising a number of distinct species. Members of the genus are commonly called firedot lichen, jewel lichen.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, gold lichens, "or ...

''.

Taxonomy

''Sclerococcum toensbergii'' was scientifically described as a new species in 2017 by the Belgian mycologist Paul Diederich. The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

was collected in the United States, specifically in Cowlitz County, Washington. It was collected on August 8, 1996, by the Norwegian lichenologist

Tor Tønsberg Tor, TOR or ToR may refer to: Places * Tor, Pallars, a village in Spain * Tor, former name of Sloviansk, Ukraine, a city * Mount Tor, Tasmania, Australia, an extinct volcano * Tor Bay, Devon, England * Tor River, Western New Guinea, Indonesia ...

. The type locality is located southwest of the summit of

Mount St. Helens Mount St. Helens (known as Lawetlat'la to the indigenous Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United St ...

, at an elevation of . The lichen was found growing on the trunk of a red alder ('' Alnus rubra''), specifically on '' Pertusaria carneopallida'' and accompanied by '' Phlyctis speirea''. The species epithet honours Tønsberg, an "expert of corticolous, crustose lichens from the Northern Hemisphere".

Description

''Sclerococcum toensbergii'' forms superficial, slightly convex structures known as , which are blackish and can be rounded, elongated, or irregular in shape. These sporodochia range from 100 to 300

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 and can sometimes merge together, often becoming poorly defined as mature

conidia A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...

(asexual spores) spread around the conidiogenous (spore-producing) area. The vegetative

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

e of this fungus are pale to medium brown and are embedded within the

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

lichen's

thallus Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms wer ...

, measuring 2 to 5 μm in diameter. The conidiophores, which are the spore-bearing structures, are grouped into dense . They are sparsely branched, pale to medium brown, and 2 to 3.5 μm thick. The conidiogenous cells, where the conidia are produced, can be monoblastic (producing a single spore) or polyblastic (producing multiple spores). These cells are terminal (at the end of the conidiophores), integrated, brown, and range in shape from somewhat spherical to

ellipsoid An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation. An ellipsoid is a quadric surface; that is, a surface that may be defined as the ...

or elongated, making them hard to distinguish from other conidiophore cells. The conidia are produced singly and are rarely seen in chains. They are dry, roughly spherical or ellipsoid, medium to dark brown, and (divided into multiple cells), typically having 6 to 15 cells visible under a microscope. The conidia measure 12.5 to 23.0 μm in length and 7.7 to 17.5 μm in width, with a length-to-width ratio (Q) of 1.0 to 1.9. These conidia often spread around the sporodochia on the host thallus. Each conidial cell is subspherical to ellipsoid, measuring 3.5 to 6 μm in diameter, with

septa The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five coun ...

(dividing walls) that are 0.5 to 1 μm thick and dark brown. The conidial walls are dark brown, 0.5 to 1 μm thick, smooth, or rarely rough.

Habitat, distribution, and ecology

At the time of its original publication, ''Sclerococcum toensbergii'' was known from two locations in Washington, USA. It was found growing on the bark-dwelling lichens ''

'' and '' Pertusaria carneopallida''. These host lichens are

asymptomatic In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asy ...

of fungal infection, and do not show visible signs of damage. The ''Pertusaria carneopallida'' thallus observed, however, had fewer apothecia (fruiting bodies) than is typically seen in this species. In 2021, the fungus was recorded from the southern

Vosges The Vosges ( , ; german: Vogesen ; Franconian and gsw, Vogese) are a range of low mountains in Eastern France, near its border with Germany. Together with the Palatine Forest to the north on the German side of the border, they form a single ...

, where it was found on ''

''. This host grows at the base of ''

Sorbus aucuparia ''Sorbus aucuparia'', commonly called rowan (UK: /ˈrəʊən/, US: /ˈroʊən/) and mountain-ash, is a species of deciduous tree or shrub in the rose family. It is a highly variable species, and botanists have used different Circumscription (taxo ...

'' (rowan) trees in areas characterized by ''

Nardus ''Nardus'' is a genus of plants belonging to the grass family, containing the single species ''Nardus stricta'', known as matgrass. It is placed in its own tribe Nardeae within the subfamily Pooideae. The name derives from ancient Greek ' () fro ...

'' grassland and dwarf shrub

heaths A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler a ...

s with ''

Vaccinium myrtillus ''Vaccinium myrtillus'' or European blueberry is a holarctic species of shrub with edible fruit of blue color, known by the common names bilberry, blaeberry, wimberry, and whortleberry. It is more precisely called common bilberry or blue whortle ...

'' (bilberry) and ''

Calluna vulgaris ''Calluna vulgaris'', common heather, ling, or simply heather, is the sole species in the genus ''Calluna'' in the flowering plant family Ericaceae. It is a low-growing evergreen shrub growing to tall, or rarely to and taller, and is found wid ...

'' (heather). This habitat is well-exposed to light and includes other lichens such as '' Lecidella elaeochroma'' and '' Rinodina malangica''. The region experiences significant snowfall during the winter, which likely covers the whole community for extended periods. This locality is situated in the area with the highest precipitation levels in northeastern France. At an elevation of , the annual precipitation reaches 1900 mm. This high humidity is possibly relevant to the occurrence of ''Sclerococcum toensbergii''. Similarly, in its Washington habitats, such as Mount St. Helens and the Olympic Peninsula, the annual precipitation is even higher, reaching 2500 mm.

References

{{Taxonbar, from=Q108346375 Eurotiomycetes Fungus species Fungi described in 2017 Fungi of the United States Taxa named by Paul Diederich Lichenicolous fungi