''Coccocarpia delicatula'' is a species of

foliicolous Foliicolous refers to the growth habit of certain lichens, algae, fungi, liverworts, and other bryophytes that prefer to grow on the leaves of vascular plants. ''Foliicolous'' simply means 'growing upon leaves' whilst epiphyllous derives from the ...

(leaf-dwelling)

foliose lichen A foliose lichen is a lichen with flat, leaf-like , which are generally not firmly bonded to the substrate on which it grows. It is one of the three most common growth forms of lichens. It typically has distinct upper and lower surfaces, each o ...

in the family

Coccocarpiaceae The Coccocarpiaceae are a family of lichen-forming in the order Peltigerales. There are three genera and about 60 species in the family. Species in this family have a widespread distribution, including boreal Boreal, northern, of the north. Deri ...

. Known only from the

Galápagos Islands The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...

and

Réunion Réunion (; ; ; known as before 1848) is an island in the Indian Ocean that is an overseas departments and regions of France, overseas department and region of France. Part of the Mascarene Islands, it is located approximately east of the isl ...

, it was described as new to science in 2011. Characterised by its rounded,

foliose A foliose lichen is a lichen with flat, leaf-like , which are generally not firmly bonded to the substrate on which it grows. It is one of the three most common lichen growth forms, growth forms of lichens. It typically has distinct upper and lo ...

thallus and unique cylindrical

isidia An isidium (plural: isidia) is a tiny, wart- or finger-like outgrowth on the thallus surface of certain lichen species. It is one of two principal types of vegetative reproduction, vegetative reproductive structures in lichens, the other being ...

, this lichen is similar in appearance to '' Coccocarpia domingensis'' but has distinct differences in isidia shape and arrangement. Found on the bark and wood of dead twigs, ''Coccocarpia delicatula'' thrives in sunny, wind- and rain-exposed environments.

Taxonomy

''Coccocarpia delicatula'' was first described by lichenologists Frank Bungartz, Frauke Ziemmeck, and

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 ...

in 2011. 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 the first author on

San Cristóbal Island San Cristóbal Island (), also known as Chatham Island, is the easternmost island in the Galápagos archipelago, as well as one of the oldest geologically. It is administratively part of San Cristóbal Canton, Ecuador. Names ''San Crist� ...

in 2008. The

species name In 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 grammatical forms, altho ...

''delicatula'' was chosen to highlight the delicate nature of the thallus compared to the more common '' Coccocarpia palmicola''.

Description

The

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 ...

of ''Coccocarpia delicatula'' is foliicolous (growing on leaves) and foliose (leafy), with a rounded shape and diameter up to 10 mm. Its are thin and flat, measuring 0.1–0.2 mm wide, linear but slightly widened towards the apex, and closely spaced. The upper surface of the lobes is blue-green when moist and plumbeous to bluish-grey when dry, featuring thin, white, longitudinal grooves. ''Coccocarpia delicatula'' can be distinguished from similar species by its , dense, uniformly cylindrical isidia that are mostly unbranched or . The isidia measure 0.1–0.3 mm long and 0.05–0.1 mm thick, covering most of the thallus interior in mature specimens. No

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 ...

pycnidia A pycnidium (plural pycnidia) is an asexual fruiting body produced by mitosporic fungi, for instance in the order Sphaeropsidales ( Deuteromycota, Coelomycetes) or order Pleosporales (Ascomycota, Dothideomycetes). It is often spherical or inve ...

have been observed, and no secondary chemical substances were detected by

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 ...

. ''Coccocarpia delicatula'' is closely related to '' C. domingensis'' and '' C. neglecta'', sharing similarities in narrow, linear thallus lobes and white longitudinal striae on the surface. The main differences between these species lie in the shape and arrangement of their isidia. '' Coccocarpia melloniorum'' is another ''Coccocarpia'' species with small thalli and narrow lobes bearing isidia; it has wider lobes than ''C. delicatula'' (up to 1 mm) and isidia.

Habitat and distribution

''Coccocarpia delicatula'' occurs in the Galápagos Islands, specifically in the transition zone on Sán Cristóbal Island. There it can be found on the bark and wood of dead twigs, thriving in sunny, wind- and rain-exposed environments. It has also been reported from

, a remote tropical island in the Mascarene archipelago.

References

{{Taxonbar, from=Q17072737 Peltigerales Lichen species Lichens described in 2011 Lichens of the Galápagos Islands Lichens of Réunion Taxa named by Robert Lücking Taxa named by Frank Bungartz