{{Short description|Species of lichen-forming fungus}} {{Use dmy dates|date=January 2026}} {{Use Australian English|date=January 2026}} {{Speciesbox | image = | image_caption = | taxon = Gyalectidium australe | authority = [[Robert Lücking|Lücking]] (2001) | mapframe = yes | mapframe-zoom = 3 | mapframe-coordinates = {{coord|17|17|S|145|34|E}} | mapframe-caption = [[type locality (biology)|Type locality]]: [[Curtain Fig National Park]], Australia }}

'''''Gyalectidium australe''''' is a species of [[lichen]]-forming [[fungus]] in the family [[Gomphillaceae]].<ref name="CoL_3HNNF"/> It is a [[foliicolous lichen|leaf-dwelling lichen]] known from [[Queensland]], Australia, and [[Yunnan]], China, forming tiny silvery-grey patches on living leaves. The species is distinguished by its very small, regularly dispersed [[thallus]] patches that produce small, horizontal, tongue-shaped reproductive structures at their margins, and it is one of the few members of its genus that develops disk-shaped [[fruiting bodies]].

==Taxonomy== ''Gyalectidium australe'' was [[species description|described]] as a new species by [[Robert Lücking]] in a 2001 revision of ''[[Gyalectidium]]'' by Ferraro and colleagues. In their treatment, it was placed near ''[[Gyalectidium caucasicum]]'' and distinguished by its very small, regular [[thallus]] patches that produce small, horizontal, {{lichengloss|liguliform}} (tongue-shaped) hyphophores at the margins.<ref name="Ferraro et al. 2001"/>

==Description== The thallus forms minutely dispersed, rounded patches about 0.2–0.3&nbsp;mm across, which together make well-defined aggregates about 2–5&nbsp;mm across. The thallus is composed of small, blister-like segments ({{lichengloss|areolate}}-{{lichengloss|bullate}}) and is heavily covered with a continuous layer of crystals, giving it a silvery to whitish-grey appearance.<ref name="Ferraro et al. 2001"/>

{{lichengloss|Hyphophores}} ([[asexual reproduction|asexual]] reproductive structures) are produced at the margin. One or several hyphophore scales may develop from each small thallus patch, so they often overlap. The scales are horizontally oriented and liguliform, about 0.1–0.2&nbsp;mm long and about 0.1&nbsp;mm broad, and are described as whitish and translucent. [[Apothecia]] (fruiting bodies) are present; they are angular-rounded, about 0.2–0.3&nbsp;mm in diameter, with a pale yellowish-brown to greyish {{lichengloss|disc}} that can be thinly {{lichengloss|pruinose}}, and a prominent whitish margin. The [[ascospore]]s are [[ellipsoid]], 30–40 × 12–18&nbsp;[[μm]]. [[Pycnidia]] were not reported.<ref name="Ferraro et al. 2001"/>

==Habitat and distribution== Ferraro and colleagues treated ''G.&nbsp;australe'' as a foliicolous member of ''Gyalectidium'' (a genus mostly found on living leaves). The species was originally known only from Queensland, Australia, and was regarded as rare in the original account. A second Queensland collection was also cited from [[Lake Eacham National Park]] (Wrights Creek).<ref name="Ferraro et al. 2001"/> It was later recorded from [[Yunnan]], China.<ref name="Aptroot et al. 2003"/>

==References== <references>

<ref name="Aptroot et al. 2003">{{cite journal |last1=Aptroot |first1=André |first2=Lidia I. |last2=Ferraro |first3=Ming-Jou |last3=Lai |first4=Hariie J.M. |last4=Sipman |first5=Laurens B. |last5=Sparrius |title=Foliicolous lichens and their lichenicolous ascomycetes from Yunnan and Taiwan |year=2003 |journal=Mycotaxon |volume=88 |pages=41–47 |url=https://www.researchgate.net/publication/216829803}}</ref>

<ref name="CoL_3HNNF">{{Catalogue of Life |id=3HNNF |title=''Gyalectidium australe'' Lücking |access-date=27 January 2026}}</ref>

<ref name="Ferraro et al. 2001">{{cite journal |last1=Ferraro |first1=Lidia I. |last2=Lücking |first2=Robert |last3=Sérusiaux |first3=Emmanuël |year=2001 |title=A world monograph of the lichen genus ''Gyalectidium'' (Gomphillaceae) |journal=Botanical Journal of the Linnean Society |volume=137 |issue=3 |pages=311–345 |doi=10.1111/j.1095-8339.2001.tb01126.x |doi-access=free}}</ref>

</references>

{{Taxonbar|from=Q17388569}}

[[Category:Gyalectidium|australe]] [[Category:Lichen species]] [[Category:Lichens described in 2001]] [[Category:Lichens of Australia]] [[Category:Lichens of China]] [[Category:Taxa named by Robert Lücking]]