''Catillaria gilbertii'' is a rare species of

saxicolous A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, giv ...

(rock-dwelling),

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

in the family Catillariaceae. It is found in the

Central Highlands of Scotland The Grampian Mountains (''Am Monadh'' in Gaelic) is one of the three major mountain ranges in Scotland, that together occupy about half of Scotland. The other two ranges are the Northwest Highlands and the Southern Uplands. The Grampian ran ...

Taxonomy

The lichen was formally described as a new species in 1996 by lichenologists Alan Fryday and Brian Coppins. The

type specimen In biology, a type is a particular 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 anchor or centralizes the ...

was collected by the first author from the

Ben Lawers National Nature Reserve Ben Lawers ( gd, Beinn Labhair) is the highest mountain in the Breadalbane region of the Scottish Highlands. It lies north of Loch Tay and is the highest peak of the 'Ben Lawers group', a ridge that includes six other Munros: Beinn Ghlas, Mea ...

(

Perthshire Perthshire ( locally: ; gd, Siorrachd Pheairt), officially the County of Perth, is a historic county and registration county in central Scotland. Geographically it extends from Strathmore in the east, to the Pass of Drumochter in the nor ...

) at an altitude of ; there, it was found growing on an east-facing

mica-schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes o ...

rock face. The

species epithet Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany) A botanical name ...

was named to honour British lichenologist Oliver Gilbert "for his pioneering work on the montane lichen vegetation of the British Isles". They noted that the naming of this species, which produces twice the usual number of

ascospore An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera o ...

s in its asci, was "particularly appropriate given the pre-disposition of the Gilbert family for producing twice the usual number of offspring at a time; Dr Gilbert himself is a twin and he also has twin daughters".

Description

The lichen has dark-brown to dark grey thallus that is bluish-grey when wet. It is

areolate Lichens are composite organisms made up of multiple species: a fungal partner, one or more photosynthetic partners, and sometimes a basidiomycete yeast. They are regularly grouped by their external appearance – a characteristic known as their ...

(with individual areoles measuring about 0.15–0.27 mm in diameter), cracked, and . Its

apothecia An ascocarp, or ascoma (), 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. Ascocarps are mo ...

are dark brown to black with a form and a diameter between 0.3–0.7 mm; there is a slightly raised (width of 0.04–0.1 mm) surrounding the flat or slightly convex . Its

s are

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

with an oblong 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 ...

shape and a single

septum In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate. Examples Human anatomy * Interat ...

, and measure 10–12 by 2.5–3 μm. The spores typically number 16 per

ascus An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera o ...

, which itself is of the ''

Catillaria ''Catillaria'' is a genus of crustose lichens in the family Catillariaceae. The genus was circumscribed by Italian lichenologist Abramo Bartolommeo Massalongo in 1852. It is the type genus of Catillariaceae, which was circumscribed by Austrian ...

''-type—with a uniformly

amyloid Amyloids are aggregates of proteins characterised by a fibrillar morphology of 7–13 nm in diameter, a beta sheet (β-sheet) secondary structure (known as cross-β) and ability to be stained by particular dyes, such as Congo red. In the hu ...

dome at the apex. Immersed in the thallus surface are conidiomata in the form of ; they are 60–80 μm in diameter and produce

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 th ...

that are ellipsoid to ovoid with dimensions of 2.5–3 by 0.8–1.4 μm. All parts of ''Catillaria gilbertii'' do not react with any of the standard chemical spot tests used to test for the presence of

lichen product Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol de ...

Habitat and distribution

''Catillaria gilbertii'' is only known to occur in the mica-schist mountains of the Scottish Central Highlands. In addition to the

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

, it has also been recorded in Glen Esk in

Angus Angus may refer to: Media * ''Angus'' (film), a 1995 film * ''Angus Og'' (comics), in the ''Daily Record'' Places Australia * Angus, New South Wales Canada * Angus, Ontario, a community in Essa, Ontario * East Angus, Quebec Scotland * Angu ...

. It is one of relatively few

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

lichens known in Scotland, and one of even fewer that inhabit the hyper-oceanic mountain habitat, above the

tree line The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowp ...

. Two similar species that occur in the same habitat are '' Catillaria chlybeia'' and '' Halecania rhypodiza''.

References

{{Taxonbar, from=Q17387120 Lecanorales Lichen species Lichens described in 1996 Lichens of Northern Europe Taxa named by Brian John Coppins