Identification Key to Pseudolagarobasidium species 1a. Basidiomes cream colored to light brown ..........................................................................................................................................2 1b. Basidiomes yellow to brown, grayish or vinaceous ..........................................................................................................................4 2a. Basidiospores 4–5.5 × 3–3.7 μm, microbinding hyphae present ........................................................................................ P. pronum 2b. Basidiospores slightly larger, microbinding hyphae absent ...............................................................................................................3 3a. Basidiomes chalky and brittle, basidiospores 5–5.8 × 3.5–4.4 μm, teeth ≤ 2 per mm, European species .................... P. conspicuum 3b. Basidiomes subceraceous, basidiospores 4.8–6.1 × 3.4–4.1 μm, teeth 2–4 per mm, Neotropical species .......................... P. pallens 4a. Basidiomes yellow to brownish orange, teeth with knobs ................................................................................................ P. venustum 4b. Basidiomes in shades of brown, gray or vinaceous, teeth smooth to slightly granulose ..................................................................5 5a. Hymenophore warty to odontioid, teeth up to 1 mm long ............................................................................................................... 6 5b. Hymenophore hydnoid, teeth generally ≥ 1 mm ............................................................................................................................... 7 6a. Basidiomes grayish, teeth up to 0.4 mm long .................................................................................................................. P. belizense 6b. Basidiomes brownish, teeth longer, up to 1 mm .............................................................................................................. P. modestum 7a. Basidiospores 3.4–4.3(−4.7) × 2.9–3.2(−3.6) μm .............................................................................................................. P. pusillum 7b. Basidiospores larger ...........................................................................................................................................................................8 8a. Teeth up to 1.8 mm long, basidiomes olive in KOH .............................................................................................. P. baiyunshanense 8b. Teeth longer, basidiomes unchanged in KOH ....................................................................................................................................9 9a. Basidiomes vinaceous when fresh, teeth up to 3.5 mm long, basidiospores 5–6(−6.5) × (3–)3.5–4(−4.5) μm............ P. subvinosum 9b. Basidiomes wood brown, teeth up to 2.5 mm long, basidiospores (4.3–)4.8–5.8(−6.5) × (2.9–)3.2–4(−4.3) μm.......... P. acaciicola

Published as part of Westphalen, Mauro C. & Motato-Vásquez, Viviana, 2022, A new species of Pseudolagarobasidium from Brazil and new insights on Cerrena (Basidiomycota, Cerrenaceae), pp. 159-168 in Phytotaxa 555 (2) on page 165, DOI: 10.11646/phytotaxa.555.2.4, http://zenodo.org/record/6875998