Fungalpedia – Note 2644, Halospora
Halospora (Zschacke) Tomas. & Cif.
Citation when using this data: Meng QF et al. – Fungalpedia.
= Polyblastia subgen. Halospora Zschacke, Hedwigia 55: 289 (1914).
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Verrucariaceae, Verrucariales, Chaetothyriomycetidae, Eurotiomycetes, Pezizomycotina, Ascomycota, Fungi
Halospora was elevated from subgenus status within Polyblastia by Ciferri et al. (1952). The species Halospora deminuta, initially classified as Polyblastia deminuta Arnold, was designated as the type species of this genus. This species had long been misidentified and considered a lichen. Roux et al. (2002) cited the original description without examining the specimen and reclassified it as Merismatium deminutum. However, Hafellner (2011) re-examined the materials, resurrecting Halospora from synonymy. He affirmed Halospora as the correct name for taxa with halonate ascospores and designated a lectotype and a paratype. He also proposed three combinations: Halospora discrepans from Polyblastia deminuta Arnold, Halospora longispora from Merismatium deminutum subsp. longisporum Cl. Roux & Nav.-Ros. and Halospora scammoeca from Merismatium scammoecum Lettau (Hafellner 2011).
Halospora is characterized by perithecioid ascomata that are immersed to semi-immersed, scattered, black, with the ostiolar region flattened or not. The ascomata wall is dark brown to black-brown in the upper part, often with a greenish to purplish violet tinge, and pale brown in the lower part, with pigmentation fading towards the center. The asci are verrucarialean, broadly cylindrical to slightly clavate, with an apex surrounded by hemiamyloid gel, containing 8 spores. The ascospores are initially middle brown, becoming dark brown, and vary from subspherical to broadly ellipsoid, ovoid, or almost oblong. They are phragmospored to submuriform or muriform with transverse and longitudinal septa when mature, thick walled, and have a distinct perispore when young. These characters highlight verrucarealean lichenicolous Polyblastia-like species with thick-walled halonate ascospores and ascomata with a typically verrucarialean shape in longitudinal section (Hafellner 2011).
Type species: Halospora deminuta (Arnold) Tomas. & Cif.
= Polyblastia deminuta Arnold.
= Merismatium deminutum (Arnold) Cl. Roux & Nav.-Ros.
Other accepted species: Species Fungorum – search Halospora.
Figure 1 – Halospora deminuta (=Merismatium deminutum) redrawn from Roux et al. (2002). a Section of ascoma. b Asci. c Periphyses. d Pseudoparaphyses. e Ascospores. Scale bars: a, b = 50 μm, c–e = 10 μm.
References
Ciferri R, Tomaselli R. 1952 – Scissioni di generi di licheni sulla base delle caratteristische del fungo. Archivio Botanico Italiano 28, 1–15.
Entry by
Meng QF, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand and School of Public Health, Zunyi Medical University, Guizhou 563000, China.
Published online 30 June 2026