''Toensbergia'' is a small

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

-forming

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the family Sporastatiaceae. These lichens form pale, granular crusts on moist soil,

moss Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...

y rocks, and

conifer Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...

bark, spreading primarily through powdery particles rather than

sexual reproduction Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote tha ...

. The genus was established in 2013 and named after the Norwegian lichenologist

Tor Tønsberg Tor Tønsberg (born 1948 in Oslo) is a Norwegian lichenologist who has made significant contributions to the taxonomy, chemistry, floristics, and phytogeography of lichens and lichenicolous fungi. Throughout his career, he has described more t ...

for his work on bark-dwelling lichens.

Taxonomy

The genus was

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

by Mika Bendiksby and Einar Timdal in 2013. The genus name honours the Norwegian lichenologist

, "in appreciation of his important work on sorediate, corticolous lichens". The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

is '' Toensbergia leucococca'', which was formerly classified in genus '' Hypocenomyce'' due to its resemblance ( morphological, chemical, and ecological) to '' Hypocenomyce xanthococca''.

Description

Species of ''Toensbergia'' spread as pale granular crusts that can merge into extensive patches or, in sheltered spots, develop into slightly raised, scale-like (subsquamulose thalli). Fresh material appears grey-white through cream to a faint green tint, depending on moisture and the density of the embedded

green alga The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( ...

l partner (a photobiont with rounded cells). A separate —the dark fungal fringe that rims many

crustose lichen Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichen ...

s—is usually absent, but some specimens show a bluish-grey to charcoal border where the fungus grows beyond the

photosynthetic Photosynthesis ( ) is a Biological system, system of biological processes by which Photoautotrophism, photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical ener ...

layer. Asexual

propagule In biology, a propagule is any material that functions in propagating an organism to the next stage in its life cycle, such as by dispersal. The propagule is usually distinct in form from the parent organism. Propagules are produced by organisms ...

s dominate: powdery

soredia Soredia are common reproduction, reproductive structures of lichens. Lichens asexual reproduction, reproduce asexually by employing simple fragmentation and production of soredia and isidia. Soredia are powdery propagules composed of fungus, fung ...

erupt from tiny nipple-like bumps on the surface, while even finer, coral-shaped break away ''en masse'', allowing the lichen to colonise nearby soil, mossy rock, or conifer bark without relying on sexual spores. Sexual structures are rarely observed in this genus; when present, they are in the form of dark red to nearly black

apothecia An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. As ...

ringed by a conspicuous rim of thallus tissue (the ), sometimes with shallow scallops along the edge. Inside each fruit-body the —the tissue capping the spore layer—is reddish-brown, and the asci are club-shaped (), each producing just two exceptionally large spores. These spores follow the ''

Pertusaria ''Pertusaria'' is a large genus of warty crustose lichen, crustose lichens in the Pertusariaceae family.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, The fruiting bodies are usually modified apothecia that im ...

'' pattern: they have walls so thick that two distinct layers are visible under a microscope and remain unpartitioned by internal cross-walls (). No separate flask-shaped

conidiomata Conidiomata (singular: Conidioma) are blister-like fruiting structures produced by a specific type of fungus called a coelomycete. They are formed as a means of dispersing asexual spores call conidia, which they accomplish by creating the blister- ...

, which many lichens use for asexual

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

, have been found. All known species synthesise alectorialic acid, a yellow-reacting compound that can be used to help confirm identifications through

thin-layer chromatography Thin-layer chromatography (TLC) is a chromatography technique that separates components in non-volatile mixtures. It is performed on a TLC plate made up of a non-reactive solid coated with a thin layer of adsorbent material. This is called the sta ...

Ecology

Ecologically, ''Toensbergia'' favours substrates that stay moist yet well-lit—bare soil on woodland banks, moss-covered boulders, and the bark of conifer trunks are typical homes—where its powdery surface can disperse easily on wind or rain splash.

Species

Genus ''Toensbergia'' comprises three accepted species: *'' Toensbergia blastidiata'' –

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

*'' Toensbergia geminipara'' *'' Toensbergia leucococca''

References

{{Taxonbar, from=Q42310402 Ostropales Lecanoromycetes genera Lichen genera Taxa described in 2013 Taxa named by Einar Timdal