Fissurina isohypocrellina

Fissurina isohypocrellina
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Lecanoromycetes
Order:	Graphidales
Family:	Graphidaceae
Genus:	Fissurina
Species:	F. isohypocrellina
Binomial name
Fissurina isohypocrellina Aptroot (2022)
Holotype: Sena Madureira, Brazil [1]

Fissurina isohypocrellina is a species of corticolous (bark-dwelling), crustose lichen in the family Graphidaceae]. ^[2] Newly described to science in 2022, it is found in the rainforests of Acre, Brazil. This species is notable within the genus Fissurina genus for the presence of isohypocrellin, a rare secondary metabolite (lichen product) that contributes to its unique wine-red apothecia (the fruiting bodies that produce spores).

Taxonomy

André Aptroot formally described Fissurina isohypocrellina in 2022. The species name reflects the presence of isohypocrellin within its apothecia (fruiting bodies), a characteristic that sets it apart from other Fissurina species. Marcela Cáceres and Aptroot collected the type specimen from the Comunidade Cuidado in the Reserva Extrativista Cazumbá-Iracema  [ pt ] (Acre, Brazil) at an elevation of 150 m (490 ft); there it was found growing on bark in a rainforest. ^[1]

Description

The thallus of Fissurina isohypocrellina is crustose, forming a continuous, thinly corticate , slightly shiny pale greenish-brown layer. It covers areas up to 5 cm (2.0 in) in diameter and is under 0.1 mm thick. The lichen does not form a prothallus (a preliminary growth around and underlying the thallus). ^[1]

The photobiont (the symbiotic algae providing nutrients through photosynthesis) is trentepohlioid . The ascomata (spore-producing structures) are immersed in the bark, linear, often curved, sometimes branched, and feature wine-red discs with carbonised (blackened) tips. ^[1]

Chemical testing of the thallus shows no reaction to ultraviolet light, nor to the C, K, KC, and P spot tests, but the presence of isohypocrellin can be confirmed through thin-layer chromatography. This pigment reacts to a potassium hydroxide solution (K) by turning a vivid green, a unique feature among lichens. ^[1]

Habitat and distribution

This species is exclusively known to grow on tree bark within the primary rainforest of Acre, Brazil. ^[1]

References

1. Aptroot, André; de Souza, Maria Fernanda; dos Santos, Lidiane Alves; Junior, Isaias Oliveira; Barbosa, Bruno Micael Cardoso; da Silva, Marcela Eugenia Cáceres (2022). "New species of lichenized fungi from Brazil, with a record report of 492 species in a small area of the Amazon Forest". The Bryologist. 125 (3): 435–467. doi:10.1639/0007-2745-125.3.433.
2. "Fissurina isohypocrellina Aptroot". Catalogue of Life . Species 2000: Leiden, the Netherlands. Retrieved 26 February 2024.