''Dirina angolana'' is a species of
corticolous
This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...
(bark-dwelling),
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 ...
in the family
Roccellaceae
The Roccellaceae are a family (biology), family of mostly lichen-forming fungi in the order Arthoniales, established by the French botanist François Fulgis Chevallier in 1826. Species in the family exhibit various lichen growth forms, growth ...
.
Found in
Angola
Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...
, it was described from specimens collected in
Luanda Province
Luanda is a province of Angola. It used to cover an area of 18,835 km2, and had a population of 6,945,386 at the Census of 16 May 2014.
The city of Luanda is the capital of the province and Angola. It serves as the country's primary port, cultur ...
. It forms pale, creamy-white crusts on
baobab
''Adansonia'' is a genus of medium-to-large deciduous trees known as baobabs ( or ). The eight species of ''Adansonia'' are native to Africa, Australia, and Madagascar but have also been introduced to other regions of the world, including Barb ...
tree bark near the coast and can be identified by a chemical
test
Test(s), testing, or TEST may refer to:
* Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities
Arts and entertainment
* ''Test'' (2013 film), an American film
* ''Test'' (2014 film) ...
that turns its surface bright red.
Taxonomy
The lichen was
formally described
A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...
as a new species in 2013 by the lichenologists Anders Tehler and Damien Ertz. The
type specimen
In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...
was collected by Tehler north of Palmeirinhas (
Luanda Province
Luanda is a province of Angola. It used to cover an area of 18,835 km2, and had a population of 6,945,386 at the Census of 16 May 2014.
The city of Luanda is the capital of the province and Angola. It serves as the country's primary port, cultur ...
). It is only known to occur in Angola, where it grows preferentially on
baobab
''Adansonia'' is a genus of medium-to-large deciduous trees known as baobabs ( or ). The eight species of ''Adansonia'' are native to Africa, Australia, and Madagascar but have also been introduced to other regions of the world, including Barb ...
tree trunks, usually near the sea. 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 (biology), taxonomy, either of these two meanings, each with its own set of rules:
* Specific name (botany) ...
refers to the country of its
type locality.
A 2017
molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
study that sampled several ''
Dirina
''Dirina'' is a genus of lichen-forming fungi in the family Roccellaceae. All ''Dirina'' species are crustose lichens with a whitish to greyish brown thallus, and live either on rock or on bark–some species can live on both. The partner is ...
'' species recovered ''Dirina angolana'' as the
sister
A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...
species to ''
Dirina astridae''.
Description
''Dirina angolana'' is a strictly bark-dwelling (
corticolous
This glossary of mycology is a list of definitions of terms and concepts relevant to mycology, the study of fungi. Terms in common with other fields, if repeated here, generally focus on their mycology-specific meaning. Related terms can be found ...
) lichen that forms a pale, creamy-white crust (
thallus
Thallus (: 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. A thallus usually names the entir ...
) 0.1–0.7 mm thick. The surface is generally smooth but may become faintly warty in places and never develops the floury bloom () seen in some other members of ''
Dirina
''Dirina'' is a genus of lichen-forming fungi in the family Roccellaceae. All ''Dirina'' species are crustose lichens with a whitish to greyish brown thallus, and live either on rock or on bark–some species can live on both. The partner is ...
''. Beneath a 25–45
μm
The micrometre (Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System ...
-thick outer skin () lies a chalk-like white
medulla
Medulla (Latin for "marrow") or medullary may refer to:
Science
* Medulla oblongata, a part of the brain stem
* Renal medulla, a part of the kidney
* Adrenal medulla, a part of the adrenal gland
* Medulla of ovary, a stroma in the center of the ...
; closer to the bark this inner layer turns looser and cottony as the fungal threads (
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 o ...
e) spread into fine fissures. No specialised vegetative
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 such as
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 or g ...
are produced.
Reproductive bodies (
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 ...
) are frequent and conspicuous. They appear as round, discs more than 1.5 mm across that sit flush on the thallus without any obvious stalk or constriction at the base. Each is covered by a uniform, grey-white powder (pruina) and is framed by a continuous, sometimes slightly wavy rim made from the lichen's own tissue (). Inside, the
asci contain eight colourless
ascospore
In fungi, an ascospore is the sexual spore formed inside an ascus—the sac-like cell that defines the division Ascomycota, the largest and most diverse Division (botany), division of fungi. After two parental cell nucleus, nuclei fuse, the ascu ...
s that are narrowly
ellipsoid
An ellipsoid is a surface that can be obtained from a sphere by deforming it by means of directional Scaling (geometry), scalings, or more generally, of an affine transformation.
An ellipsoid is a quadric surface;  that is, a Surface (mathemat ...
, 23–30 μm long and about 4–5 μm wide. A simple chemical
spot test
Spot analysis, spot test analysis, or a spot test is a chemical test, a simple and efficient technique where analytic assays are executed in only one, or a few drops, of a chemical solution, preferably in a great piece of filter paper, without usin ...
with commercial
bleach
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color from (i.e. to whiten) fabric or fiber (in a process called bleaching) or to disinfect after cleaning. It often refers specifically t ...
(the C test) turns the thallus surface bright red, while the medulla remains unreactive and the disc colours only faintly—an indication of
erythrin,
lecanoric acid
Lecanoric acid is a chemical produced by several species of lichen.ubChem - Lecanoric acid"> Lecanoric acid is classified as a polyphenol and a didepside, and it functions as an antioxidant. It is an ester of orsellinic acid with itself.
The acid ...
and three yet-unidentified compounds that characterise this species.
References
{{Taxonbar, from=Q107643454
angolana
Lichen species
Lichens described in 2013
Lichens of South Tropical Africa
Taxa named by Damien Ertz
Taxa named by Anders Tehler