{{Short description|Species of lichen}} {{Speciesbox | image = Calogaya pusilla 63115267.jpg | image_caption = growing on a rock in Berlin, Germany | taxon = Calogaya pusilla | authority = (A.Massal.) Arup, Frödén & Søchting (2013) | synonyms_ref = <ref name="Species Fungorum synonymy"/> | synonyms = *''Physcia pusilla'' {{small|A.Massal. (1852)}} *''Amphiloma pusillum'' {{small|(A.Massal.) Körb. (1859)}} *''Placodium pusillum'' {{small|(A.Massal.) Anzi (1860)}} *''Teloschistes pusillus'' {{small|(A.Massal.) Trevis. (1869)}} *''Gasparrinia pusilla'' {{small|(A.Massal.) P.Syd. (1887)}} *''Caloplaca murorum'' var. ''pusilla'' {{small|(A.Massal.) Sandst. (1912)}} *''Caloplaca pusilla'' {{small|(A.Massal.) Zahlbr. (1926)}} }}
'''''Calogaya pusilla''''' is a species of saxicolous (rock-dwelling), crustose lichen in the family Teloschistaceae. ''Calogaya pusilla'' is common in Europe, and has been recorded from a few locations in the United States. Its typical habitat is on vertical, calcareous rock surfaces. It also occurs on walls with mortar.<ref name="Knudsen & Kocourková 2014"/>
==Taxonomy==
It was originally formally described in 1852 by Italian lichenologist Abramo Bartolommeo Massalongo, who placed it in genus ''Physcia''. The type specimen was collected in Veneto, Italy.<ref name="Massalongo 1852"/> It has undergone several changes of genus in its taxonomic history, including transfers to ''Caloplaca'', ''Placodium'', and ''Teloschistes''.<ref name="Species Fungorum synonymy"/> In 2013, it was placed in the newly circumscribed genus ''Calogaya''.<ref name="Arup et al. 2013"/>
==Description==
''Calogaya pusilla'' is a small but visually striking lichen that forms neat, rosette-shaped growths measuring 1–3 centimetres in diameter. The thallus (main body of the lichen) appears yellow to orange, occasionally with a pinkish tint, and grows closely attached to its substrate. Around the edge, the lichen forms short, broad, flattened {{lichengloss|lobes}} about 2 mm long and 1.5 mm wide. These lobes are typically convex and swollen, giving them a plump appearance, and may be divided by small furrows. A distinctive feature of this species is the frequent presence of a white, powdery coating ({{lichengloss|pruina}}) on the surface of the lobes.<ref name="Cannon et al. 2024"/>
The central area of the lichen consists of convex {{lichengloss|granules}} that are often obscured by numerous apothecia (fruiting bodies). These {{lichengloss|disc}}-shaped apothecia can reach up to 1.0 mm in diameter and are typically densely crowded in the central portion of the lichen. When young, each apothecium has a flat, orange to brownish-orange disc surrounded by a noticeable yellow to orange rim ({{lichengloss|exciple}}). As the apothecium matures, the disc becomes convex and the rim becomes less prominent.<ref name="Cannon et al. 2024"/>
Under the microscope, the spore-producing structures reveal further identifying features. The tips of the sterile filaments (paraphyses) within the apothecia are swollen, measuring 6–8 micrometres (μm) in diameter. The spores ({{lichengloss|ascospores}}) are ellipsoidal, measuring 10–15 μm long by 5–7 (occasionally 8) μm wide, with a cross-wall (septum) that is 2–4 μm thick, occupying approximately one-fourth to one-fifth of the spore's length.<ref name="Cannon et al. 2024"/>
When tested with potassium hydroxide solution (K), both the thallus and apothecia turn purple, which is a key chemical characteristic for identifying this species.<ref name="Cannon et al. 2024"/>
==References== {{Reflist|refs=
<ref name="Massalongo 1852">{{cite journal |last1=Massalongo |first1=A. |year=1852 |title=Monograpfia del licheni blasteniospori |journal=Atti del Reale Istituto Veneto di Scienze, Lettere ed Arti |volume= ser.2:t.1-3|series=2 |page=59 |language=it |url=https://www.biodiversitylibrary.org/page/7783817}}</ref>
<ref name="Arup et al. 2013">{{cite journal |last1=Arup |first1=Ulf |last2=Søchting |first2=Ulrik |last3=Frödén |first3=Patrik |title=A new taxonomy of the family Teloschistaceae |journal=Nordic Journal of Botany |volume=31 |issue=1 |year=2013 |pages=016–083 |doi=10.1111/j.1756-1051.2013.00062.x|bibcode=2013NorJB..31...16A }}</ref>
<ref name="Cannon et al. 2024">{{cite book |last1=Cannon |first1=P. |last2=Arup |first2=U. |last3=Coppins |first3=B. |last4=Aptroot |first4=A. |last5=Sanderson |first5=N. |last6=Simkin |first6=J. |last7=Yahr |first7=R. |year=2024 |title=Teloschistales, including ''Brigantiaea'' (Brigantiaeaceae), ''Megalospora'' (Megalosporaceae) and ''Amundsenia'', ''Athallia'', ''Blastenia'', ''Calogaya'', ''Caloplaca'', ''Cerothallia'', ''Coppinsiella'', ''Flavoplaca'', ''Gyalolechia'', ''Haloplaca'', ''Huneckia'', ''Kuettlingeria'', ''Leproplaca'', ''Marchantiana, ''Olegblumea'', ''Polycauliona'', ''Pyrenodesmia'', ''Rufoplaca'', ''Rusavskia'', ''Sanguineodiscus'', ''Scythioria'', ''Solitaria'', ''Squamulea'', Teloschistes'', ''Variospora'', ''Xanthocarpia'', ''Xanthomendoza'' and ''Xanthoria'' (Teloschistaceae) |series=Revisions of British and Irish Lichens |volume=43 |pages=23–24 |url=https://britishlichensociety.org.uk/sites/default/files/Teloschistales.pdf}} {{OA}}</ref>
<ref name="Knudsen & Kocourková 2014">{{cite journal |last1=Knudsen |first1=Kerry |last2=Kocourková |first2=Jana |year=2014 |title=Notes on the California Lichen Flora 6: New Records |journal=Opuscula Philolichenum |volume=13 |pages=4–7 |doi=10.5962/p.386061 |url=https://www.researchgate.net/publication/260478757|doi-access=free }}</ref>
<ref name="Species Fungorum synonymy">{{cite web |title=Synonymy. Current Name: ''Calogaya pusilla'' (A. Massal.) Arup, Frödén & Søchting, Nordic Jl Bot. 31(1): 39 (2013) |url=http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=802322 |publisher=Species Fungorum |access-date=4 July 2022}}</ref>
}}
{{Taxonbar |from1=Q25412987 |from2=Q107482572 |from3=Q108239175 |from4=Q108423194 |from5=Q107693178 |from6=Q21254414}}
Category:Teloschistales Category:Lichen species Category:Lichens described in 1852 Category:Lichens of Europe Category:Lichens of the United States Category:Taxa named by Abramo Bartolommeo Massalongo