Hyalopyrenia
Hyalopyrenia is a fungal genus in the division Ascomycota. Its placement within Ascomycota are uncertain, and it has not been placed with certainty in any class, order, or family. Both the genus its only species, Hyalopyrenia japonica, were described as new to science by the Japanese lichenologist Hiroshi Harada in 1996.
Taxonomy
Hyalopyrenia was described in 1996 by Hiroshi Harada from material collected on friable rock in a forest in Chiba Prefecture, central Japan. The genus is monospecific, with only its type species, Hyalopyrenia japonica. Hyalopyrenia has a thin, inconspicuous crustose thallus with a Trentepohlia photobiont. Its perithecia are half-immersed and have a completely colourless wall. The asci are bitunicate and non-amyloid, with a distinct, and they produce transversely septate, hyaline spores; paraphyses and are present. Its taxonomic placement was considered uncertain, with no clear close affinities among other. The holotype is deposited in the herbarium of the Natural History Museum and Institute, Chiba. In Japan, the species has been given the vernacular name シロザネゴケ.The paraphyses are sparse and can be overlooked beside the prominent periphyses, which could lead to confusion with members of Verrucariaceae. Because the paraphyses and periphyses are very similar in form and are mainly distinguished by their position relative to the asci, the "periphyses" in this genus may differ in development from those typical of Verrucariaceae. Developmental studies may be needed to clarify their nature. The genus resembles Strigula in some microscopic and Pyrenula in occasionally forming a, but it differs from genera such as Aspidothelium and Dermatocarpon.
Description
The thallus forms a crust on rock and often grows partly within the substrate, so it may be almost invisible in the field. Where visible, it forms greenish-grey patches that closely follow the rock surface; the patches may be smooth or slightly warted, sometimes with small fissures. Anatomically it lacks a distinct outer layer. It consists of an upper with Trentepohlia and a lower, endolithic zone of sparse, colourless hyphae within the rock.Perithecia are produced singly or in small groups and are typically half-immersed in the thallus or substrate, measuring about 0.15 to 0.5 mm across. They are very pale pinkish-brown and often roughened, and the upper part is commonly split by lengthwise cracks. The ostiole may be hard to see or more evident and can extend into a short beak. The perithecial wall is colourless and becomes strongly thickened in the upper part. The includes prominent, mostly simple periphyses and sparse, almost simple paraphyses.
The asci are, and non-amyloid, with a distinct. Each ascus contains eight spores. The ascospores are hyaline and thin-walled and are typically 7-septate, measuring about 30–36 μm × 6–8 μm. They are slightly curved to nearly straight, and an was reported as absent. Pycnidia were not observed in the type material.