Phylogenetic classification of arbuscular mycorrhizal fungi: new species and higher-ranking taxa in Glomeromycota and Mucoromycota (class Endogonomycetes) Author Tedersoo, Leho Mycology and Microbiology Center, University of Tartu, 2 Liivi, 50409 Tartu, Estonia & Department of Zoology, College of Science, King Saud University, 12371 Riyadh, Saudi Arabia Author Magurno, Franco 0000-0002-3117-8149 Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Jagiellońska 28, 40 - 032 Katowice, Poland Author Alkahtani, Saad 0000-0001-7381-5110 Department of Zoology, College of Science, King Saud University, 12371 Riyadh, Saudi Arabia Author Mikryukov, Vladimir 0000-0003-2786-2690 Mycology and Microbiology Center, University of Tartu, 2 Liivi, 50409 Tartu, Estonia text MycoKeys 2024 2024-08-09 107 249 271 journal article 10.3897/mycokeys.107.125549 Endogonales Jacz. & P. A. Jacz. , emend. Tedersoo Type family. Endogonaceae Paol. Description. Fruiting body hypogeous or on debris, globose, irregular, sometimes resupinate, 1–10 mm in diam., may be composed of aggregated zygosporangial clusters, with zygospores formed on apposed suspensors. Hyphae of fruiting body tissue coenocytic, aseptate, sometimes with secondary septa that form micropores. Reproductive structures as zygosporangia, rarely azygosporangia (co-existing with zygosporangia in Endogone pisiformis ) or chlamydospores (in Vinositunica ), distributed randomly or radially in fruiting bodies, 100–700 μm diam., with yellow granular contents. Zygosporangial wall comprises outer sporangiothecium with 1–4 openings and inner eusporium with no openings. Azygosporangia rare, with a single-layered wall and separated from the single suspensor by a gametangial septum. Chlamydospore wall continuous, multilayered, with dense subtending hyphae, lacking septa. Forms a monophyletic group in Endogonomycetes as the least inclusive clade covering accessions EUK 1601498, EUK 1100757, LC 002628 , LC 431107 , EUK 1104693 and UDB 025468. Notes. Includes taxa with or without fruiting bodies and with ectomycorrhizal, arbuscular mycorrhizal and saprotrophic lifestyles. Endogonales harbours Endogonaceae , Jimgerdemanniaceae and Vinositunicaceae families, as well as seven potentially family-level taxa, collectively comprising> 200 species based on ITS and LSU sequences. Order description is adapted from Morton and Benny (1990) and Yamamoto et al. (2020) .