Pyrenula triangularis is a species of corticolous (bark-dwelling) crustose lichen in the family Pyrenulaceae.[1] The species is characterised by its distinctive conical fruiting bodies (perithecia) that typically grow in groups of two to four and merge to form a single triangular or irregularly shaped mass on the bark surface. It produces relatively large ascospores divided by multiple cross-walls and one to three lengthwise walls, a spore type known as muriform .
This species produces a very thin, gray‑brown crust framed by a narrow black line. Its perithecia are conical and sit on the surface, measuring 0.6–1.0mm across. They usually occur in groups of two to four; the perithecia in a group merge their walls and pores to form a single superficial mass (a pseudostroma) that often looks triangular from above. In vertical section each conical component is 1.0–2.0mm wide. The pores are lateral rather than apical and are often depressed and whitish. The hamathecium is clear, without oil droplets. Each ascus yields eight ascospores arranged in two rows. The spores are muriform —divided by five transverse walls and one to three longitudinal walls—and measure 25–31μm long and 12–16μm wide. Their internal cavities are rounded, and a thickened inner wall is present at the tips. No asexual structures are known in this species.[2]
Habitat and distribution
As of its original description, Pyrenula triangularis was known only from the type collection in Guyana.[2] No additional location were reported by Aptroot in his 2021 world key to the genus.[3]
123Aptroot, André; Sipman, Harrie J.M.; Cáceres, Marcela Eugenia da Silva (2013). "Twenty-one new species of Pyrenula from South America, with a note on over-mature ascospores". The Lichenologist. 45 (2): 169–198 [195]. doi:10.1017/S0024282912000734.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
