Full name: Hebeloma pamphiliense Cittadini, Lezzi & Contu (2008)
Published: Bollettino della Associazione Micologica ed Ecologica Romana 73-74 (1-2): 6 (2008)
Taxonomic status: This is a Tubaria.
Notes: (Note that there appears to be an error in the Latin diagnosis when compared with the Italian text. In Latin the word “juventute” is used, which means youth, in the Italian text “per vetustà” clearly means with age or when old, which makes more sense, i.e. the stipe becomes darker with age and when handled).

Types: ITALY: Roma, Roma-citta, Parco di Villa Pamphili (approx. 41.89°N, 12.44°E, alt. approx. 80 m a.s.l.) on cupule in deciduous woodland under Quercus ilex, 20 Jan. 2008, M. Cittadini, T. Lezzi, det: M. Contu, M. Cittadini, T. Lezzi (Holotype. herbarium acc. no. MCVE 23394, HJB1000152).

Original diagnosis: Venusta et parva species, Hebelomata in mente revocans sed sporae amyloideae et sublaeves vel leaves. Pileus 10-14 mm, leviter carnosus, in juventute hemisphericus dein convexus et denique applanatus, ad medium obtuse umbonatus, margine leviter involute, glaber, levis, interdum floccis flavo-brunneis ad marginem obtectus, hygrophanus, ad discum cremeo-flavus, versus marginem albus et iove pluvio leviter striatus. Lamellae modice confertae, emarginatae vel adnato-decurrentes, in juventute albae dein flavescentes, acie concolori, flocculosa. Stipe 40-60 x 35-70 mm, cylindricus vel ad basim leviter inflatus, leviter flexuosus, albidis sed in juventute vel tactu inferne brunnescens, sericeus, superne floccis albis ornatus, plenus dein fistuloso-farctus et denique cavus. Velum deest. Caro sat fragilis, fibrosa, alba sed cremeo-ochraceo ad basim stipites. Odor acidis vel flores in mente revocans; sapor dulcis. Sporarum pulvis alba. Sporae 6,6-8,3 x 4,8-6,4 μm; Qm = 1,4, hyalinae, tenuitunicatae, in Aureo Chresylico leviter metachromaticae, late ellipsoideae vel ovoideae, leves vel leviter asperulatae, pariete plerumque modice amyloidea. Basidia 26-35 x 6-8 μm, plerumque tetraspora. Pleurocystidia nulla. Cheilocystidia 25-32 x 4,5-6,5 μm, numerosa, cylindrico-flexuosa, superne maxima parte capitulata, hyaline, tenuitunicata. Pileipellis ex hyphis cylindraceis laxe intertextis 2-7 (-8) μm latis, brunneis, incrustatis constituta; hypocutis ex hyphis inflatis usque ad 20 μm latis constituta. Caulocutis ex hyphis paralellis efformata, caulocystidia nulla. Fibulae numerosae. Habitatio in herbido loco, prope Quercum ilicem, gregaria sed haud caespitosa, ad quisquilis lignosis vel ad cupulas glandae ilicis, hieme.

English translation: Charming and small species, reminiscent of a Hebeloma, but with almost smooth to smooth, amyloid spores. Pileus 10–14 mm, slightly fleshy, hemispherical when young then convex and finally applanate, at centre bluntly umbonate, with slightly involute margin, glabrous, smooth, occasionally covered near margin with yellowish-brown flocks, hygrophanous, cream-coloured yellowish on the disc, white towards margin and after rain slightly striate. Lamellae moderately crowded, emarginate to adnate-decurrent, white when young then yellowing, with concolourous, floccose edge. Stipe 40–60 × 35–70 mm, cylindrical or slightly broadened at base, slightly flexuous, white but turning brown from base upwards with age or when handled, shiny, with small white flocks at apex, fistulose-stuffed then hollow. Veil absent. Context rather fragile, fibrous, white to creamy-ochraceous in the base of the stipe. Odour acidulous or reminiscent of flowers, taste mild. Spore print white. Spores 6.6–8.3 × 4.8–6.4 μm; Qm = 1.4, hyaline, thin-walled, in Cresyl-blue slightly metachromatic, broadly ellipsoid to ovoid, smoothor slightly asperulate, usually slightly amyloid. Basidia 26–35 × 6–8 μm, usually four-spored. Pleurocystidia absent. Cheilocystidia 25–32 × 4.5–6.5 μm, abundant, cylindrical-flexuous, capitulate at apex, hyaline, thin-walled. Pileipellis made up of loosely interwoven cylindrical hyphae 2–7(–8) μm wide, brown, encrusted; hypocutis made up of hyphae to 20 μm wide. Caulocutis made up of parallel hyphae, caulocystidia absent. Clamp connections abundant. Growing in grassy place, near Quercus ilex, gregarious but not caespitose on pieces of wood, acorns and cupulae of Quercus ilex in winter.

Commentary: This light-spored taxon was described in Hebeloma. We havestudied the holotype both morphologically and molecularly. It appears to be a species of Tubaria (W.G.Sm.) Gillet, possibly Tubaria furfuracea (Pers.) Gillet, results which have been illustrated in a recent paper (Vizzini et al. 2014). The partial ITS sequence from the holotype of Hebeloma pamphiliense confirms the placement of the isotype by Vizzini et al. (2014). However, it should be noted that the molecular identification of T. furfuracea and allies is by no means clear. What is called by common consent the “T. furfuracea complex” or “Tubaria furfuracea s. lat.” (Matheny et al. 2007, Vizzini et al. 2014; fig. 5), contains in Europe one or two ITS species, but it is not clear how these ITS species relate to described species. Furthermore, this clade is not the only one competing for the name of T. furfuracea or species from its context. There are at least three distinct clades (see also Vizzini et al. 2014) including ITS sequences named by acclaimed mycologists, suggesting that type studies of European Tubaria species may not necessarily support the synonymy of Hebeloma pamphiliense with T. furfuracea or any of the members of the described species of the T. furfuracea complex once the taxonomy and nomenclature of these taxa have been cleared up. Antonín et al. (2012 and literature cited therein) report on additional albinotic collections of Tubaria (see fig. 5). One of these (BRNM737651 JX126808) clusters with another group of T. furfuracea collections that, judging from ITS data, belong to a species that is not included in the same T. furfuracea complex as Hebeloma pamphiliense. Tubaria furfuracea is the type species of Tubaria and one could argue that all of the instances of T. furfuracea as well as the type of Hebeloma pamphiliense will probably remain in Tubaria, irrespective of the clade in which the type of T. furfuracea will nest. However, the generic limits of Tubaria are phylogenetically not clear-cut in relation to Flammulaster and Phaeomarasmius (see also Matheny et al. 2007, Vizzini et al. 2014). Although it is likely that the type of H. pamphiliense is part of the group of taxa that will remain in Tubaria, at least as long as the identities of Flammulaster carpophilus and Phaeomarasmius excentricus (according to Kirk 2018 considered synonymous with P. rimulincola) are not clear, it does appear premature to transfer Hebeloma pamphiliense to Tubaria.