Taxonomy
Pseudocalenia was circumscribed in 2023 by Amanda Xavier-Leite, Marcela Cáceres, and Robert Lücking to accommodate the species Pseudocalenia solorinoides, [4] which was previously classified in the genus Calenia . [5] Molecular phylogenetics studies demonstrated that P. solorinoides was not closely related to true Calenia species, but instead showed closer affinities to the morphologically distinct genera Roselviria and Santricharia . The genus name alludes to its previous classification in Calenia. [4]
While the immersed apothecial structure of Pseudocalenia bears superficial resemblance to some other species like Calenia bullatinoides and Bullatina aspidota , molecular evidence indicates these similarities evolved independently multiple times within the Gomphillaceae rather than indicating close relationships. [4]
Description
Pseudocalenia is a foliicolous lichen, meaning it grows on living leaves. The fungal body (thallus) appears scattered or dispersed rather than forming a continuous coating, with distinctive swollen, bubble-like patches that rise up from the leaf surface. Unlike many related lichens, Pseudocalenia lacks the hair-like projections called sterile setae on its surface. [4]
The reproductive structures (apothecia) are completely immersed within these raised thallus patches, giving them a sunken appearance. These structures lack a proper margin , with the surrounding thallus tissue effectively serving as their border. The excipulum comprises tightly packed, parallel fungal threads (hyphae) and appears colourless under the microscope. [4]
The species produces specialised reproductive structures called hyphophores , which are short, bristle-like projections that emerge from the margins of the thallus patches. These hyphophores are primarily white but develop distinctive blackened tips. They produce specialised fungal threads called diahyphae , which have characteristic terminal segments that are either spindle-shaped ( fusiform ) or club-shaped ( clavate ). [4]
A unique feature of P. solorinoides is that it produces just a single ascospore per reproductive sac (ascus), rather than the multiple spores typical of many lichens. These spores are muriform , meaning they are divided by both vertical and horizontal walls into multiple compartments, creating a brick wall-like appearance when viewed under magnification. [4]
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