Archaeospora (J. B. Morton & D. Redecker) emend. Magurno, Uszok, Esmaeilzadeh-Salestani, Tedersoo, M. B. Queiroz & B. T. Goto

Esmaeilzadeh-Salestani, Keyvan, Queiroz, Mariana Bessa de, Mikryukov, Vladimir, Uszok, Sylwia, Goto, Bruno Tomio, Tedersoo, Leho & Magurno, Franco, 2025, Morphological and phylogenetic analysis of the early-diverging lineage of Glomeromycota suggest two new genera and recombinations in Archaeosporales, MycoKeys 124, pp. 249-273 : 249-273

Archaeospora (J. B. Morton & D. Redecker) emend. Magurno, Uszok, Esmaeilzadeh-Salestani, Tedersoo, M. B. Queiroz & B. T. Goto

Genus description.

Spores acaulosporoid, entrophosporoid and / or glomoid formed singly or in aggregates in the substrate or occasionally within roots. Acaulosporoid and entrophosporoid spores hyaline or white to light yellow, small (22–114 µm diam), globose to subglobose, rarely ellipsoid to ovoid. Subcellular spore structure composed of two walls: the outer wall with one-two hyaline layers, and the inner wall with one to three permanent, flexible to semi-flexible layers. None of the layers in either wall stain with Melzer’s reagent. Sporiferous saccule hyaline to subhyaline, with a delicate mono- to bi-layered wall continuous with the two outer spore wall layers; usually collapsed or detached in extraradical spores. Glomoid spores hyaline to white, small (22–31 µm diam), with a bi-layered wall. Forming mycorrhizal structures with weak reaction in Trypan blue.

Type genus.

Archaeospora trappei (R. N. Ames & Linderman) J. B. Morton & D. Redecker , Mycologia 93 (1): 183 (2001).

Basionym.

Acaulospora trappei R. N. Ames & Linderman , Mycotaxon 3 (3): 566 (1976).

Other species.

Archaeospora europaea Oehl, Palenz., Sánchez-Castro, V. M. Santos & G. A. Silva , Sydowia 71: 131 (2019).

Archaeospora myriocarpa ( Spain, Sieverd. & N. C. Schenck) Oehl, G. A. Silva, B. T. Goto & Sieverd., Mycotaxon 117: 430 (2011).

Archaeospora schenckii (Sieverd. & S. Toro) C. Walker & A. Schüßler , The Glomeromycota: a species list with new families and new genera: 53 (2010).

Archaeospora undulata (Sieverd.) Sieverd., G. A. Silva, B. T. Goto & Oehl , Mycotaxon 117: 430 (2012).

Ecology and distribution.

Environmental sequencing data show that the genus has a broad distribution, with records from 38 countries across tropical, subtropical, temperate, and subpolar regions in Africa, the Americas, Europe, Asia, and Oceania (Suppl. material 7). It has been detected in diverse biomes, including broadleaf and coniferous forests, woodlands, grasslands (montane and flooded), shrublands, deserts, freshwater river systems, and a variety of anthropogenic habitats such as croplands, rangelands, villages, and urban areas (Suppl. material 5).