Hebeloma xerophilum - A non-current Hebeloma species

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

Full name: Hebeloma xerophilum Rudn.-Jez. [as “xerophila”] (1967)
Published: Acta Mycol. 3: 183 (1967)
Taxonomic status: Heterotypic synonym of H. velatum
Types: POLAND: Kampinoski National Park (Kampinoski Park Narodowy) (approx. 52.19°N, 20.34°E, alt. approx. 90 m a.s.l.) on sandy soil under Salix sp., 17 Jul. 1963, W. Rudnicka-Jezierska (Lectotype. herbarium acc. no. WA0326361, HJB1000141). Lectotype designated by Vesterholt, Windahlia 20: (1993) page 61.

The holotype collection was mixed; part was designated as lectotype.

Original diagnosis: Pileus convexus dein explanatus usque ad 2,5 cm latus, umbone lutescente non hygrophanus, glaber, pallido-brunneus, margine obscurior non involute. Stipes subaequalis sed basi subincrassatus (bulbosus elongatus), 4-5 x 0,8 cm; subfibrillosus, farctus, supra flocculosus, pileo subconcolor. Caro crassa, compacta, pileo subconcolor, immutabilis, inodora. Lamellae ad 0,5 cm latae, satis distantes, alternantes, adnatae vel emarginatae, pallidae, badio-carneae. Cystidia clavata, 55-80 x 6-11 μm, hyalina, satis sparsa in acie lamellarum. Basidia clavata quadrispora, 22-27 x 10 μm. Sporae 6-9 x 3-6 μm, ellipsoideae, paulo punctatae. Fungus ad Hebeloma fastibile similis est, sporis et cystidiis majoribus. Habitatio: in sabularis immersa inter Salicem.

English translation: Pileus convex then expanded up to 2.5 cm broad, with umbo becoming yellow, not hygrophanous, glabrous, pale brown, with non-involute, darker margin. Stipe subequal or with slightly broadened base (elongated bulb), 4–5 × 0.8 cm, subfibrillose, stuffed, floccose at apex, same colour as pileus. Context thick, compact, same colour as pileus, not changing colour, without odour. Lamellae up to 0.5 cm broad, moderately distant, alternating, adnate to emarginate, pale, brown-incarnate. Cystidia clavate, 55–80 × 6–11 μm, hyaline, moderately sparse along lamella edge. Basidia clavate, four-spored, 22–27 × 10 μm. Spores 6–9 × 3–6 μm, ellipsoid, weakly punctate. Similar to Hebeloma fastibile, but with larger spores and cystidia. Habitat in wet sandy soil under Salix.

Commentary: Vesterholt (1993) studied the original material and found it was a mixed collection, part of which had ellipsoid spores, but much larger than the dimensions mentioned in the protologue, and part which had amygdaloid spores. He designated the former basidiomes as lectotype. At the time he believed that these spores represented Hebeloma psammophilum Bon. During this study we re-examined the lectotype and confrmed the presence of rather large ellipsoid spores (average 10.5 × 6.0 µm). Using both morphological and molecular methods we were able to confirm that the lectotype conforms to H. dunense. Thus this taxon: = Hebeloma dunense L. Corb. & R. Heim.