Porina monilisidiata is a species of corticolous (bark-dwelling), crustose lichen in the family Trichotheliaceae, first described in 2016. This species is characterised by its shiny, olive-green thallus with numerous isidia and low conical ascomata.
Porina monilisidiata was formally described by the lichenologists Gothamie Weerakoon and André Aptroot in 2016. The type specimen was collected in the Sinharaja Forest Reserve, Sri Lanka, on the bark of a tree on 17 February 2015.
The thallus of Porina monilisidiata is, smooth or slightly, covering areas up to 10abbr=onNaNabbr=on in diameter, shiny, continuous, and thin. The colour of the thallus is olive green, surrounded by a thin black . are numerous,, the same colour as the thallus, mostly simple, but some are branched, wavy to a bit, cylindrical, approximately 0.05 mm in diameter and 0.3–0.8 mm high. The are . Ascomata are low conical, approximately 0.7–1.2 mm in diameter, fully covered by a thin layer of thallus through which the dark ascomata appear grey-brown, with a black, 0.1–0.3 mm wide ostiole. consistently have nine septa, and measure 65–75 by 10–13 μm. were not observed.
The thallus of Porina monilisidiata does not react with any of the standard chemical spot tests. Thin-layer chromatography analysis did not detect any substances in the lichen.
This species is found on trees in wet lowland tropical rainforests and at the time of its publication, was known only from Sri Lanka.