| Anisomeridium globosum | |
|---|---|
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Dothideomycetes |
| Order: | Monoblastiales |
| Family: | Monoblastiaceae |
| Genus: | Anisomeridium |
| Species: | A. globosum |
| Binomial name | |
| Anisomeridium globosum Aptroot D.S.Andrade & M.Cáceres (2014) | |
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Anisomeridium globosum is a species of corticolous (bark-dwelling), crustose lichen in the family Monoblastiaceae. [1] This species is characterised by its greyish-green thallus and its almost globose (spherical) ascomata (fruiting bodies). The ascospores are 1-septate, meaning they are divided into two sections, and measure 8–10.5 μm by 4.5–6 μm. The septum (dividing wall) is distinctly submedian, such that the lower cell is only about a quarter of the size of the upper cell. [2]
The type specimen of Anisomeridium globosum was collected from the Refúgio de Vida Silvestre Mata do Junco in Capela, Sergipe, Brazil, at an elevation of about 150 m (490 ft). The thallus is thin, shiny, and greyish-green, surrounded by an irregular white prothallus (a border around the thallus) about 1 mm wide. The ascomata are almost globose (more or less spherical), 0.3–0.45 mm in diameter, and superficial (situated on the surface) in the bark but completely covered by a thin layer of thallus. The walls of the ascomata are carbonised (blackened) all around. The ostioles (openings) are apical (at the top), black, and protrude through the thallus. The hamathecium , the tissue between the asci, does not contain oil droplets, and its filaments interconnect above the asci. The asci are cylindrical, measuring 80–95 μm by 5.5–7.5 μm, and have a small ocular chamber. The ascospores are hyaline (translucent), uniseriate (arranged in a single row), with a pointed lower end and a rounded upper end. Pycnidia (small asexual fruiting bodies) have not been observed. Chemically, the thallus does not fluoresce under ultraviolet light, and no substances were detected using thin-layer chromatography. [2]
Anisomeridium globosum is found on smooth bark in undisturbed Atlantic rainforests and is only known to occur in Brazil. This species is notable within its genus for having a corticate (having a cortex or outer layer) thallus, which is relatively rare. Other species with a corticate thallus tend to have larger ascospores and differ in other key characteristics. [2]