Hebeloma pallida - A non-current Hebeloma species

According to our data Hebeloma pallida is not the name of a current valid species of Hebeloma. Our database has records for the following similar names

Full name: Hebelomina pallida Dessì & Contu (1993)
Published: Micologia e vegetazione Mediterranea 8 (2): 104 (1993)
Taxonomic status: This is a Gymnopilus.
Notes: Current name: Gymnopilus pallidus (Dessì & Contu) Contu, Boll. Assoc. Micol. Ecol. Romana 24(nos 73-74): 17 (2008).

Types: Sardinia, prov. Cagliari, Serramanna, on dead wood of Eucalyptus, 5 Jul. 1992, P. Dessi, M. Contu (Holotype CAG herb. M. Contu 92/269; holotype not seen).

Original diagnosis: Pileus 1-2 cm latus, semiglobosus vel explanatus, haud umbonatus, siccus, levis, haud hygrophanus, candide albus. Lamella sat confertae, adnatae, albae, acie concolore. Stipes 2-3.5 x 0.3-0.5 cm, cylindraceus, ad basim attenuatus, fibrillosus, albo-pruinosus, concolor pileo. Caro parce conspicua, albida, immutabilis; odor debilis, sapor amarus. Sporae 7.5-9 (10.3) x 5.2-6 (6.9) μm, hyalinae, dextrinoidae, cyanophilae, regulariter ellipsoideae, interdum apice angustatis, leves. Basidia 30-36 x 8.2-9.7 m, tetraspora, clavata, fibulata. Lamellarum trama regularis. Pleurocystidia nulla. Cheilocystidia 22.5-37.5 x 6-7.5 μm, capitulum 3.7-6.7 μm, lageniformia vel lagenocapitulata, tenuitunicata. Pilei cutis ex hyphis radialibus, cylindraceis, 3-7.5 μm latis constituta, leviter gelata; pigmento tenui, intraparietalis. Fibulae numerosae. Habitat ad lignum putridum Eucalypti camadulensi in regione mediterranea. Species rare.

English translation: Pileus 1–2 cm broad, hemispherical to expanded, not umbonate, dry, smooth, not hygrophanous, brightly white. Lamellae rather crowded, adnate, white, with concolourous edge. Stipe 2–3.5 × 0.3–0.5 cm, cylindrical, attenuate towards base, fibrillose, white pruinose, concolourous with pileus. Context hardly conspicuous [very thin], white, not staining; odour weak, taste bitter. Spores 7.5–9 (10.3) × 5.2–6 (6.9) μm, hyaline, dextrinoid, cyanophilous, regularly ellipsoid, sometimes with narrowed apex, smooth. Basidia 30–36 × 8.2–9.7 μm, fourspored, clavate, Trama of lamellae regular. Pleurocystidia absent. Cheilocystidia 22.5–37.5 × 6–7.5 μm, capitulum 3.7–6.7 μm wide, lageniform of lageniform-capitate, thin-walled. Pileipellis made up of radially arranged hyphae, 3–7.5 m wide, slightly gelatinized; pigment thin, intraparietal [in the walls]. Clamp connections abundant. Growing on rotten wood of Eucalyptus camadulensis in Mediterranean region. Rare.

Commentary: This species is described as growing on the wood of Eucalyptus. It is not a Hebeloma according to the protologue. Contu (in Cittadini et al. 2008) transferred the species to Gymnopilus, based on its similarity to Gymnopilus neerlandicus (Hebelomina neerlandica) and its association in the field with numerous basidiomes of G. cf. penetrans on wood, a Eucalyptus camaldulensis stump. Unfortunately, and despite many requests, we have been unable to loan the type and hence cannot comment further on this taxon.