''Pulchrocladia retipora'', commonly known as the coral lichen, is a
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
fruticose lichen
A fruticose lichen is a form of lichen fungi that is characterized by a coral-like shrubby or bushy growth structure. It is formed from a symbiotic relationship of a photobiont such as green algae or less commonly cyanobacteria and one, two or m ...
in the family
Cladoniaceae. Found predominantly in
Australasia
Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different context ...
, its
habitats
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...
range from the
Australian Capital Territory
The Australian Capital Territory (ACT), known as the Federal Capital Territory until 1938, is an internal States and territories of Australia, territory of Australia. Canberra, the capital city of Australia, is situated within the territory, an ...
to New Zealand's
North
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography.
Etymology
T ...
and
South Island
The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...
s, and even the Pacific region of
New Caledonia
New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...
, where it grows in coastal and alpine
heathland
A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and is characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a coole ...
s. The lichen features coral-like branches and subbranches with numerous intricate, netlike perforations. It is known by multiple names, with some sources referring to it by its
synonym
A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...
''Cladia retipora'', or the
common name
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...
lace lichen.
The lichen was first
scientifically collected by the French biologist
Jacques Labillardière
Jacques-Julien Houtou de Labillardière (28 October 1755 – 8 January 1834) was a French biologist noted for his descriptions of the flora of Australia. Labillardière was a member of a voyage in search of the Jean-François de Galaup, comte ...
on board
Bruni d'Entrecasteaux
Antoine Raymond Joseph de Bruni, chevalier d'Entrecasteaux (; 8 November 1737 – 21 July 1793) was a French Navy officer, explorer and colonial administrator who served as the Governor of Isle de France (Mauritius), governor of Isle de Fran ...
's 1792 expedition. Labillardière erroneously classified it as an
alga
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...
rather than a lichen. ''Pulchrocladia retipora'' holds the distinction of being the first Australian lichen to be scientifically documented. It is now 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 ...
of the genus ''
Pulchrocladia''. This genus was established in 2018 as a result of a
molecular phylogenetics
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 ...
-led restructuring of the Cladoniaceae.
Taxonomy
The species was first
formally described by
Jacques Labillardière
Jacques-Julien Houtou de Labillardière (28 October 1755 – 8 January 1834) was a French biologist noted for his descriptions of the flora of Australia. Labillardière was a member of a voyage in search of the Jean-François de Galaup, comte ...
in 1806, as ''Baeomyces reteporus''. 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 from
Tasmania
Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...
.
This sample was obtained as part of the botanical
collections he made during Labillardière's 1791–1794 voyage to the
South Seas
Today the term South Seas, or South Sea, most commonly refers to the portion of the Pacific Ocean south of the equator. The term South Sea may also be used synonymously for Oceania, or even more narrowly for Polynesia or the Polynesian Triangle ...
with the French explorer
Antoine Bruni d'Entrecasteaux
Antoine Raymond Joseph de Bruni, chevalier d'Entrecasteaux (; 8 November 1737 – 21 July 1793) was a French Navy officer, explorer and colonial administrator who served as the Governor of Isle de France (Mauritius), governor of Isle de Fran ...
in an unsuccessful search for the French naval officer
Jean-François de Galaup, comte de Lapérouse
Commodore (rank), Commodore Jean François de Galaup, comte de Lapérouse (; 23 August 1741 – ) was a French Navy officer and explorer. Having enlisted in the Navy at the age of 15, he had a successful career and in 1785 was appointed to lea ...
. Labillardière had first collected the lichen in 1792, and published the description in ''Novae Hollandiae Plantarum Specimen'', erroneously describing the lichen as an alga.
According to the Australian lichenologist
Rex Filson, this lichen was the first to be described for Australia.
In its
taxonomic
280px, Generalized scheme of taxonomy
Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation ...
history, the species has been shuffled to several genera, some of which are no longer used or have been
synonymized with other genera.
In 1814, the Swedish botanist
Erik Acharius
Erik Acharius (10 October 1757 – 14 August 1819) was a Swedish botanist who pioneered the Taxonomy (biology), taxonomy of lichens and is known as the "father of lichenology". Acharius was famously the last pupil of Carl Linnaeus.
Life
Ac ...
changed the spelling of the
specific epithet
In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...
to ''retipora'' (from ''retepora'') when he introduced the
new combination
In Taxonomy (biology), biological taxonomy, a combinatio nova (abbreviated comb. nov. or n. comb.) refers to the formal renaming of an organism's scientific name when it is transferred to a different genus, reclassified within a different specie ...
''Cenomyce retipora''.
It is not known for certain if Acharius's change was intentional, as he still referred to the
basionym
In the scientific name of organisms, basionym or basyonym means the original name on which a new name is based; the author citation of the new name should include the authors of the basionym in parentheses. The term "basionym" is used in both botan ...
as ''Baeomyces retiporus'' Labill. The term ''rete'' translates to "net", and the correct
connecting vowel in such compounds is "i", making ''retiporus'' the appropriate spelling. The original spelling by Labillardière is considered an
orthographical variant
In biology, within the science of Nomenclature, scientific nomenclature, i.e. the naming of organisms, an orthographical variant (abbreviated orth. var.) in botany or an orthographic error in zoology, is a spelling mistake, typing mistake or writi ...
due to the lack of evidence indicating a deliberate choice of spelling. Since ''retipora'' is widely recognized, the current spelling has been maintained to avoid confusion.
Other genera that have housed the species are ''
Pycnothelia'' (Fée, 1825), ''
Cladonia'' (Fries, 1826), ''
Cladina
''Cladonia'' is a genus of moss-like lichenized fungi in the family (biology), family Cladoniaceae. They are the primary food source for reindeer/caribou. ''Cladonia'' species are of economic importance to reindeer-herders, such as the Sami peop ...
'' (Nylander, 1868), ''
Cladia'' (Nylander, 1876), and ''
Clathrina'' (Johann Müller, 1883).
Nylander proposed the genus ''Cladia'' in 1870 to contain three ''Cladonia'' species based on their shared trait of having a cortex made of (stuck together), longitudinally aligned filaments. In 1883,
the Swiss botanist
Johannes Müller Argoviensis
Johann Müller (9 May 1828 – 28 January 1896) was a Swiss botanist who was a specialist in lichens. He published under the name Johannes Müller Argoviensis to distinguish himself from other naturalists with similar names.
Biography
Müller ...
suggested that the name ''Cladia'' could be confused with ''
Cladium
''Cladium'' (fen-sedge, sawgrass or twig-sedge) is a genus of large sedges, with a nearly worldwide distribution in tropical and temperate regions. These are plants characterized by long, narrow (grass-like) leaves having sharp, often serrated ( ...
'' (a genus of
sedge
The Cyperaceae () are a family of graminoid (grass-like), monocotyledonous flowering plants known as wikt:sedge, sedges. The family (biology), family is large; botanists have species description, described some 5,500 known species in about 90 ...
s), and proposed a replacement genus ''Clathrina''. Nylander persisted with the genus name ''Cladia'', a decision that was largely accepted by later taxonomists. ''Cladia retiporus'' was the most prevalent name for the lichen for more than a century.
''Pulchrocladia retipora'' is now 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 ...
of genus ''
Pulchrocladia'', which was
circumscribed in 2018 by Soili Stenroos, Raquel Pino-Bodas,
Helge Thorsten Lumbsch
Helge Thorsten Lumbsch (born 1964) is a German-born lichenology, lichenologist living in the United States. His research interests include the phylogeny, taxonomy (biology), taxonomy, and phylogeography of lichen-forming fungi; lichen diversity; ...
, and
Teuvo Ahti following a large-scale
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 ...
analysis of the family
Cladoniaceae.
It is
commonly known as the coral lichen,
or the lace lichen.
Description

Like most species in the family Cladoniaceae, ''Pulchrocladia retipora'' has a growth form, meaning it has both a primary (horizontal) and secondary (vertical)
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 ...
. The is nodular (i.e. with small raised areas or swellings), white, and only lasts for a short period.
are the that originate from the primary thallus. The podetia are typically up to tall, white to pale grey in colour, sometimes tinged pinkish or yellowing or superficially blackening at tips. They are rigid when dry, but become spongy when wet. They are irregularly or dichotomously branched, forming cushiony clumps. The wall is highly perforated (about 5–11 perforations per centimetre), with large, round to ellipsoidal holes. The surface of the podetium is continuously and lacks
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 ...
. The inner
medulla is made of twisted strands of
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 with a cobweb-like form.
The lichen, nonetheless, generates soredia-like clusters of algal cells and hyphae within the strands of the inner medulla.
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 ...
occur infrequently. When present, they are small, black, , and crowd together at the ends of small, terminal branches (). The colour of the
hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in oth ...
ranges from dark reddish-brown to black.
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 have dimensions of 25–27 by 5
μm. The
conidiomata end on branchlets, and are covered with translucent slime; they produce curved or straight
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 ...
measuring 6 by 1 μm.
Specimens collected in Australia tend to have a brownish colouring, while New Zealand specimens range from pure white to grey, to grayish-green, or slightly yellowish.
The
photobiont
A lichen ( , ) is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualistic relationship. partner is
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 ( ...
e from the ''
Trebouxia
''Trebouxia'' is a unicellular green alga. It is a photosynthetic organism that can exist in almost all habitats found in polar, tropical, and temperate regions.Erokhina, L. G., Shatilovich, A. V., Kaminskaya, O. P., & Gilichinskii, D. A. (2004 ...
''. Occasionally, free-living algae become trapped in the irregularly intertwined hyphae of the medulla.
Usnic acid
Usnic acid is a naturally occurring dibenzofuran derivative found in several lichen species with the formula C18H16O7. It was first isolated by German scientist W. Knop in 1844 and first synthesized between 1933 and 1937 by Frank H. Curd and Al ...
and
atranorin are the major
secondary compounds present in ''Pulchrocladia retipora''. Other compounds present in smaller quantities, identifiable 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 ...
, are
protolichesterinic and
ursolic acids,
as well as
rangiformic acid and
norrangiformic acids in many cases.
Usnic acid is thought to be responsible for the
antimicrobial
An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used aga ...
,
antiviral
Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Antiviral drugs are a class of antimicrobials ...
and
cytotoxic
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are toxic metals, toxic chemicals, microbe neurotoxins, radiation particles and even specific neurotransmitters when the system is out of balance. Also some types of dr ...
biological activity
In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or ...
of ''Pulchrocladia retipora'' lichen extracts tested in ''
in vitro
''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...
'' experiments.
The hue of ''P. retipora'' is determined by the concentration of usnic acid in the thallus, leading to a colour spectrum that ranges from an opaque greyish-white through yellowish-white to a distinct yellow.
''Pulchrocladia retipora'' and ''
P. corallaizon'' are closely related species, and their similarities may lead to confusion in identifying them. However, one can distinguish them by observing the inner-medulla of ''Pulchrocladia retipora'', which is characteristically tightly packed. In the more mature of ''C. corallaizon'', there may be areas where the inner medulla is missing or appears less dense. Nonetheless, the medulla always remains compacted in the top branches of the pseudopodetia, ensuring it never appears stranded or corticated.
Habitat and distribution

''Pulchrocladia retipora'' is widely distributed throughout Australasia. In Australia, it has been recorded from the
Australian Capital Territory
The Australian Capital Territory (ACT), known as the Federal Capital Territory until 1938, is an internal States and territories of Australia, territory of Australia. Canberra, the capital city of Australia, is situated within the territory, an ...
,
New South Wales
New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...
,
Queensland
Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...
,
Victoria
Victoria most commonly refers to:
* Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India
* Victoria (state), a state of Australia
* Victoria, British Columbia, Canada, a provincial capital
* Victoria, Seychelles, the capi ...
, and
Tasmania
Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...
. In New Zealand, it is known from both the
North
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography.
Etymology
T ...
and
South Island
The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...
s as well as the
Antipodes Islands
The Antipodes Islands (, ) are inhospitable and uninhabited volcanic islands in subantarctic waters to the south of – and territorially part of – New Zealand. The archipelago lies to the southeast of Stewart Island / Rakiura, and to the ...
,
Auckland Islands
The Auckland Islands ( Māori: ''Motu Maha'' "Many islands" or ''Maungahuka'' "Snowy mountains") are an archipelago of New Zealand, lying south of the South Island. The main Auckland Island, occupying , is surrounded by smaller Adams Island ...
,
Campbell Island, and
Chatham Islands
The Chatham Islands ( ; Moriori language, Moriori: , 'Misty Sun'; ) are an archipelago in the Pacific Ocean about east of New Zealand's South Island, administered as part of New Zealand, and consisting of about 10 islands within an approxima ...
. In the Pacific, it occurs in
New Caledonia
New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...
.
The coral lichen is common in subalpine peat
bog
A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and musk ...
s; it is often found in association with the lichens ''
Cladonia confusa'', ''
Rexiella sullivani'', and ''
Stereocaulon ramulosum''. It is found on peaty soils among
tussocks or in
heath
A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and is characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a coole ...
s comprising ''
Dracophyllum
''Dracophyllum'' is a genus of plants belonging to the family Ericaceae, formerly Epacridaceae. There are 61 species in the genus, mostly shrubs, but also cushion plants and trees, found in New Zealand, Australia, Lord Howe Island and New Caledon ...
'' and ''
Leptospermum
''Leptospermum'' is a genus of shrubs and small trees in the myrtle family Myrtaceae commonly known as tea trees, although this name is sometimes also used for some species of ''Melaleuca''. Most species are endemic to Australia, with the greate ...
'', most often at the margins of ''
Nothofagus
''Nothofagus'', also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere, found across southern South America (Chile, Argentina) and east and southeast Australia, New Zealand, New Guin ...
'' forests, in
fellfield
A fellfield or fell field comprises the environment of a slope, usually alpine or tundra, where the dynamics of frost (freeze and thaw cycles) and of wind give rise to characteristic plant forms in scree interstices.
Soil dynamics
The freeze-tha ...
, or rarely on surfaces such as rocks, logs, and sand dunes.
In the
moorland
Moorland or moor is a type of Habitat (ecology), habitat found in upland (geology), upland areas in temperate grasslands, savannas, and shrublands and the biomes of montane grasslands and shrublands, characterised by low-growing vegetation on So ...
s of the Meredith Range area in Tasmania, it thrives in well-drained, elevated locations, especially close to decomposing
buttongrass hummocks.
The lichen replicates
vegetatively when new podetia grow from fragments of old podetia.
It has highly variable growth rates, ranging from less than 1 mm per year to up to a few centimetres per year.
It has been noted to grow in clusters, sometimes up a metre in diameter. The unique morphology of the lichen helps it to survive the exposed heaths it inhabits, as the coral structure increases
gas exchange
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a b ...
, moderates temperature extremes, and maximises light and water access.
''Pulchrocladia retipora'' grows in cushion-like growths ranging in diameter from about to .
The New Zealand botanist William Martin remarked finding square metre-sized cushions in the area of
Lewis Pass
Lewis Pass is the northernmost of the three main mountain passes through the Southern Alps in the South Island of New Zealand. With an elevation of 907 metres, it is slightly lower than Arthur's Pass and higher than Haast Pass.
The pass is ...
in Canterbury, New Zealand. Lichen cushions about the size of a
football
Football is a family of team sports that involve, to varying degrees, kick (football), kicking a football (ball), ball to score a goal (sports), goal. Unqualified, football (word), the word ''football'' generally means the form of football t ...
have been observed growing on the mountain range in Australia's
Grampians National Park
The Grampians National Park, commonly known as the Grampians, is a national park located in the Grampians region of Victoria, Australia. The Jardwadjali name for the mountain range itself is Gariwerd.
The national park is situated between ...
. According to Martin, the lichen forms large growths only occur in
subalpine
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
zones, with lowland forms being only in size.
Uses and research

The complex net-like structures of ''Pulchrocladia retipora'' are known as
fenestra
A fenestra (fenestration; : fenestrae or fenestrations) is any small opening or pore, commonly used as a term in the biology, biological sciences. It is the Latin word for "window", and is used in various fields to describe a pore in an anatomy, ...
tions.
Rosmarie Honegger referred to the thallus of this species as "likely to be among the most complex vegetative structures ever produced in the fungal kingdom".
The appearance of the lichen has been described as "of considerable beauty resembling lace or coral". As a result, it has been used in
floral decoration and
architectural
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and construction, constructi ...
design.
In his review of ''
The Lichenologist'' journal's cover designs, German lichenologist
Robert Lücking
Robert Lücking (born 1964) is a German lichenologist, known for his extensive research on foliicolous lichens (lichens that live on leaves) and his significant contributions to the taxonomy, ecology, and biodiversity of fungi and lichens. He e ...
highlighted the design of volume 37, issue 1, from 2005, as particularly striking. This issue featured an image of ''Pulchrocladia retipora'' set against a blue-themed background.
Thallus development
Understanding the branching pattern of ''Pulchrocladia retipora'' is important for comprehending its unique
developmental biology
Developmental biology is the study of the process by which animals and plants grow and develop. Developmental biology also encompasses the biology of Regeneration (biology), regeneration, asexual reproduction, metamorphosis, and the growth and di ...
, and some studies have focused on this aspect. The first structure to emerge from the primary thallus is a meristem, which is a solid bundle of tissue comprising only fungal cells. Two adjacent
meristem
In cell biology, the meristem is a structure composed of specialized tissue found in plants, consisting of stem cells, known as meristematic cells, which are undifferentiated cells capable of continuous cellular division. These meristematic c ...
bundles give rise to the erect secondary thallus, the
podetium. These bundles continue to split , resulting in groups of three meristem bundles. Because the development of same-age bundles is unequal, the developmental differences become more pronounced as the meristem bundles grow farther apart. Splitting of the meristem is not synchronized between approximately same-age bundles; consequently, one meristem bundle or one side of the podetium can grow beyond the others. During its early development, the meristem of ''P. retipora'' undergoes slight bends and twists. These early changes become noticeable later in the form of varying angles between the meristem bundles. Perforations that are developmentally unrelated to the central perforation tend to occur early in the lichenised tissue
distal
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...
to the meristem, while perforations that occur between meristem bundles happen later in development.
Resynthesis
The ''Pulchrocladia retipora'' lichen thallus has been successfully resynthesized from isolated
mycobiont
A lichen ( , ) is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualistic relationship. and photobiont under laboratory conditions. In these experiments, lichen
primordia, consisting of fungal
mycelia
Mycelium (: mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are fo ...
and enclosed algae appear after about one month. After four months, the cultures form small scales that are the starting units for the development of the complex
hyphal
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 ...
network that becomes the thallus. Later, the scales differentiate into columns that grow together vertically to form a thin network, and more hyphae join and fuse together to strengthen and stabilize the network. Eventually, algae
colonise the network prior to further development of the inner medulla and connecting of the fenestrations. In the laboratory, the entire process takes about two years.
Biomonitoring
The Baseline Air Pollution Station in Tasmania (part of the
World Meteorological Organization
The World Meteorological Organization (WMO) is a List of specialized agencies of the United Nations, specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology an ...
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Global Atmosphere Watch network) has used ''Pulchrocladia retipora'' as a
bioindicator
A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...
to identify how
atmospheric nitrogen and
sulphur
Sulfur (American spelling and the preferred IUPAC name) or sulphur (English in the Commonwealth of Nations, Commonwealth spelling) is a chemical element; it has Symbol (chemistry), symbol S and atomic number 16. It is abundance of the chemical ...
deposition in Tasmania is affected by
human pollution.
References
Cited literature
*
External links
Herbarium records of ''Pulchrocladia retipora'' at the Consortium of North American Lichen Herbaria
{{Taxonbar, from=Q108303740
Cladoniaceae
Lichen species
Lichens described in 1806
Lichens of Australia
Lichens of New Caledonia
Lichens of New Zealand
Taxa named by Jacques Labillardière