''Pyrenula inspersicollaris'' is a species of corticolous (bark-dwelling), crustose lichen in the family

Pyrenulaceae The Pyrenulaceae are a family of fungi in the order Pyrenulales. The family was first named by German botanist Gottlob Ludwig Rabenhorst in 1870. Species in the family have a widespread distribution, but are especially prevalent in the tropics, wh ...

. It is similar to the pantropical species '' Pyrenula septicollaris'' but can be distinguished by its inspersed (a tissue layer in the ascomata containing oil droplets). The are 3- septate, meaning they are divided into four sections, and measure 17–20

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

by 5.5–6.5 μm. The type specimen of ''Pyrenula inspersicollaris'' was collected from the southern slope of

Serra de Itabaiana National Park Serra de Itabaiana National Park ( pt, Parque Nacional Serra de Itabaiana) is a national park in the state of Sergipe, Brazil. Location The park lies in the Atlantic Forest biome, and covers . It was created on 15 June 2005, and is administered b ...

Areia Branca, Sergipe Areia Branca is a municipality located in the Brazilian state of Sergipe. Its population was 18,686 (2020) and it covers . Areia Branca has a population density of 120 inhabitants per square kilometer. It is located from the state capital of Ser ...

, Brazil, at an elevation of approximately . The thallus is thin, dark brown, somewhat glossy, and lacks

pseudocyphella Pseudocyphellae (singular ''pseudocyphella'') are structures in lichens that appear as tiny pores on the outer surface (the cortex of the lichen. They are caused when there is a break in the cortex of the lichen, and the medullary hyphae extend t ...

e (tiny pores on the surface) and a (a thin border around the thallus). The ascomata are emergent (partially embedded) in the bark and fully covered by the thallus. They are (pear-shaped), 0.3–0.5 mm in diameter, and usually occur in clusters of 2–7 with fused ostioles (openings). The walls of the ascomata are completely (blackened), and the ostioles are lateral (located on the sides). The hamathecium contains

hyaline A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none. Histopathology Hyaline cartilage is ...

(translucent) oil droplets. The ascospores are brown, irregularly (arranged in two rows), and have mostly rounded internal cavities separated from the wall by a thick layer. ''Pyrenula inspersicollaris'' does not have pycnidia (small asexual fruiting bodies). Chemically, the thallus does not fluoresce under ultraviolet light, and no lichen products were detected using thin-layer chromatography. ''Pyrenula inspersicollaris'' grows on smooth bark in undisturbed Atlantic rainforests and is only known from Brazil. This species is notable for its inspersed hamathecium, which distinguishes it from ''Pyrenula septicollaris'' that also grows in the same area.

References

{{Taxonbar, from=Q108307623 inspersicollaris Lichen species Lichens described in 2014 Lichens of Northeast Brazil Taxa named by André Aptroot Taxa named by Marcela Cáceres

See also

References