# Carbacanthographis

Carbacanthographis is a genus of corticolous (bark-dwelling) lichens in the family Graphidaceae. The genus was circumscribed by German lichenologists Bettina Staiger and Klaus Kalb in 2002. An updated worldwide key to the genus was published in 2022 that added 17 new species. This revision allowed for further identification of undescribed species from other collections, and subsequently, 14 species were added in 2023 from the Amazonian lowland forests of Brazil and the Guianas.

## Description

Genus Carbacanthographis bears a strong resemblance to the genera Allographa and Graphis, with which it shares several characteristics, such as Trentepohlia-like photobionts, a typically carbonised (blackened) lirelliform excipulum, and colourless, transversely septate or muriform ascospores.
One of the main distinguishing features of Carbacanthographis is its unique apical structure of the excipulum. Unlike in Allographa and Graphis, where the excipulum's two lips close and the hamathecium extends into the fissure, in Carbacanthographis, the excipulum extends above the hamathecium, leaving an open fissure. This fissure's walls are covered at the tips by warty periphysoids, which are challenging to observe and rarely seen. Additionally, the excipulum may have somewhat radiating and apically emergent, smooth hyphae.
The growth pattern of the carbonised excipulum in Carbacanthographis results in less evident striate lirellae compared to many species of Graphis and Allographa. Clearly striate lirellae in Carbacanthographis are typically visible only when the excipulum is abraded, as seen in species like C. latispora.
The ascospores in Carbacanthographis also show notable differences. While in Allographa and Graphis, the spore lumina become rounded to lentiform with a strong I+ blue-violet reaction due to endospore deposition, in Carbacanthographis, some species have rounded to lentiform lumina without a positive I-reaction. In other species, there is little or no endospore formation, and the septa remain thin, with ascospores that may or may not exhibit a positive I-reaction.
The hamathecium's inspersion in Carbacanthographis consists of minute droplets approximately 0.5–1 μm wide, in contrast to the larger, unevenly sized oil-like droplets found in Graphis and Allographa. This difference in inspersion further aids in distinguishing Carbacanthographis from its close relatives.

## Species

As of May 2024, Species Fungorum (in the Catalogue of Life) accept 43 species in Carbacanthographis.
* Carbacanthographis acanthoamicta Feuerstein & Lücking (2022) – Papua New Guinea
* Carbacanthographis acanthoparaphysata Feuerstein & Lücking (2022) – Papua New Guinea
* Carbacanthographis aggregata Feuerstein & Lücking (2022) – Peninsular Malaysia
* Carbacanthographis albolirellata B.O.Sharma & Khadilkar (2011) – Tamil Nadu
* Carbacanthographis alloafzelii (A.W.Archer) A.W.Archer (2007) – South Solomons
* Carbacanthographis amazonica Feuerstein & Lücking (2022) – French Guiana
* Carbacanthographis amicta (Nyl.) Staiger & Kalb (2002)
* Carbacanthographis aptrootii Feuerstein & Lücking (2022) – Yunnan, China
* Carbacanthographis brasiliensis Feuerstein & Lücking (2022) – São Paulo, Brazil
* Carbacanthographis bulbosa Aptroot & M.Cáceres (2023) – Brazil
* Carbacanthographis candidata (Nyl.) Staiger & Kalb (2002)
* Carbacanthographis chionophora (Redinger) Staiger & Kalb (2002)
* Carbacanthographis clandestinospora Aptroot & M.Cáceres (2023) – Brazil
* Carbacanthographis cleitops (Fée) Lücking (2009)
* Carbacanthographis coccospora (Aptroot) Aptroot & Lücking (2009)
* Carbacanthographis crassa (Müll.Arg.) Staiger & Kalb (2002)
* Carbacanthographis cristata Aptroot & M.Cáceres (2023) – Brazil
* Carbacanthographis denudata Sipman (2023) – Guyana
* Carbacanthographis garoana (Nagarkar & Patw.) Pushpi Singh & Kr.P.Singh (2020)
* Carbacanthographis granulosa Sipman (2023) – Guyana
* Carbacanthographis halei Feuerstein & Lücking (2022) – Sarawak
* Carbacanthographis hertelii Kalb & Staiger (2004) – Australia
* Carbacanthographis hillii (A.W.Archer) A.W.Archer (2007)
* Carbacanthographis indica B.O.Sharma & Khadilkar (2011) – Meghalaya
* Carbacanthographis induta (Müll.Arg.) Lücking (2009)
* Carbacanthographis inspersa Staiger (2002) – Brazil
* Carbacanthographis inspersomarcescens Aptroot & M.Cáceres (2023) – Brazil
* Carbacanthographis iriomotensis (M.Nakan.) M.Nakan. & Kashiw. (2003)
* Carbacanthographis isidiata Sipman (2023) – Guyana
* Carbacanthographis latispora Feuerstein & Lücking (2022) – Venezuela
* Carbacanthographis latisporoides Sipman (2023) – Guyana
* Carbacanthographis lucidocleitops Sipman (2023) – Guyana
* Carbacanthographis megalospora Feuerstein & Lücking (2022) – Espírito Santo
* Carbacanthographis minutissima Sipman (2023) – Guyana
* Carbacanthographis multiseptata Feuerstein & Lücking (2022) – Venezuela
* Carbacanthographis multiseptatoides Sipman (2023) – Guyana
* Carbacanthographis muriformis E.A.Tripp & Lendemer (2010) – Florida, USA
* Carbacanthographis nematoides (Leight.) Feuerstein & Lücking (2022)
* Carbacanthographis nigra Sipman (2023) – Guyana
* Carbacanthographis nitida Aptroot & M.Cáceres (2023) – Brazil
* Carbacanthographis novoguineensis Feuerstein & Lücking (2022) – Papua New Guinea
* Carbacanthographis protocristata Sipman (2023) – Guyana
* Carbacanthographis pseudorustica Feuerstein & Lücking (2022) – Sarawak
* Carbacanthographis salazinica (A.W.Archer) A.W.Archer (2005) – Australia
* Carbacanthographis salazinicoides Feuerstein & Lücking (2022) – Papua New Guinea
* Carbacanthographis sipmaniana Feuerstein & Lücking (2022) – Sabah
* Carbacanthographis sorediata B.O.Sharma, Makhija & Khadilkar (2010) – Tamil Nadu
* Carbacanthographis spongiosa Feuerstein & Lücking (2022) – Sergipe
* Carbacanthographis stictica Staiger & Kalb (2002) – Amazonas
* Carbacanthographis subalbotecta Staiger & Kalb (2002) – Brazil
* Carbacanthographis subchionophora Feuerstein & Lücking (2022) – Papua New Guinea
* Carbacanthographis submultiseptata Lücking, N.Marín & B.Moncada (2023) – Colombia
* Carbacanthographis tetrinspersa Aptroot (2022) – Brazil
* Carbacanthographis triphoroides (M.Wirth & Hale) Lücking (2009)
* Carbacanthographis uniseptata Kalb & Aptroot (2018) – Australia
* Carbacanthographis violaceospora Kukwa & Flakus (2013) – Bolivia
Former species;
* C. chilensis (Zahlbr.) Lücking (2013) = Redonographa chilensis, Redonographaceae
* C. marcescens (Fée) Staiger & Kalb (2002) = Graphina marcescens, Graphidaceae
* C. saxiseda (Zahlbr.) Bungartz (2010) = Redonographa saxiseda, Redonographaceae
* C. saxorum (Egea & Torrente) Lücking & Bungartz (2010) = Redonographa saxorum, Redonographaceae