434 Persoonia – Volume 36, 2016

Xerocomellus poederi Fungal Planet description sheets 435

Fungal Planet 458 – 4 July 2016 poederi G. Moreno, Heykoop, Esteve-Rav., P. Alvarado & Traba, sp. nov.

Etymology. Named after Reinhold Pöder, Austrian mycologist and special- sequences GenBank, KU355477, KU355490); idem, paratype AH 44053; ist in , who passed away in August 2015. idem, paratype AH 45804 (ITS, LSU sequences GenBank, KU355478, KU355491); Lugo, Concello de O Corgo, Finca O Fia, in humus of Quercus Classification — , Boletales, . robur, 2 Nov. 2013, G. Moreno, J.M. Traba & J.M. Castro-Marcote, paratype AH 45855; A Coruña, Vimianzo, in humus of Quercus robur, Corylus avellana Cap 1.2–5.5 cm broad, convex becoming applanate convex, and Laurus nobilis, 29 Aug. 2015, J.M. Castro-Marcote, paratype AH 45803 sometimes depressed at centre, pale brown (Mu 7.5YR 6/3, (ITS, LSU sequences GenBank, KU355480, KU355491); Orense, Leiro, in 6/4), brown pinkish (Mu 5YR 6/3, 6/4) to dark brown when humus of Quercus robur, 23 Nov. 2013, J.M. Castro-Marcote, paratype AH mature (Mu 5YR 3/1, 3/2, 3/3), becoming darker in herbarium 45805 (ITS, LSU sequences GenBank, KU355479, KU355492). Xerocomel- specimen; surface dry, smooth, the epicutis cracking in age lus chrysenteron: Spain, Madrid, La Barranca, Navacerrada, in humus of with reddish tinges in the cracks on the upper part (Mu 10R Pinus sylvestris, 29 Oct. 2013, V. Córdoba, AH 44023 (ITS, LSU sequences GenBank, KU355474, KU355487); Segovia, Ermita de Hontanares, Riaza, 4/6, 4/8); context in cap whitish, reddish under the epicutis, in humus of Quercus pyrenaica, 20 June 2010, D. Saavedra, Y. Fernández staining slightly bluish when bruised or cut. Margin irregular, & L. Rubio-Casas, AH38968 (ITS, LSU sequences GenBank, KU355473, concolorous to slightly paler, not hygrophanous nor striate. KU355486). : Spain, Segovia, Ermita de Hontan- Tubes up to 0.8 mm in length, depressed around the , ven- ares, Riaza, in humus of Quercus pyrenaica, 12 June 2010, L. Rubio-Roldán tricose, narrower towards the margin, whitish to pale yellowish & L. Rubio-Casas, AH 38964 (ITS, LSU sequences GenBank, KU355481, KU355493). : pain when young (Mu 2.5Y 8/3, 8/4) then yellowish (Mu 2.5Y 7/4, Xerocomellus ripariellus S , Madrid, Velilla de San Anto- nio, in humus of Populus alba, 3 July 2010, M. Martín, AH38971 (ITS, LSU 7/6), turning slightly bluish when bruised or cut. Stem 2.5–6 × sequences GenBank, KU355482, KU355494). subtomentosus: 0.3–0.6 cm, cylindrical, solid, tapered downward, often curved, Spain, Ávila, El Tiemblo, in humus of Castanea sativa and Quercus pyrenaica, fragile, dark reddish (Mu 10R 3/4, 3/6), yellowish at the apex 27 June 2010, J.A. Rodea, AH38974 (ITS sequence GenBank, KU355483); (Mu 2.5Y 8/4, 8/6), surface slightly granulose; context in stem Toledo, Real de San Vicente, in humus of Quercus ilex ssp. ballota, 23 Nov. whitish at the apex, dark red in the lower half or lower two thirds, 2013, R. Losada, AH 44076 (ITS, LSU sequences GenBank, KU355484, KU355495); Segovia, Fresno de Cantespino, in humus of Quercus pyrenaica turning slightly bluish when bruised or cut. Odour and taste not and Q. ilex ssp. ballota, 6 Sept. 2013, J.M. Barrasa, AH45790 (ITS, LSU se­- distinctive. Spore-print olive brown (Mu 2.5Y 5/3, 5/4). Spores quences GenBank, KU355485, KU355496). (10.5–)11–16(–17) × 4–5.5(–6) µm, av. 11.9–14.6 × 4.4–5 Notes — Xerocomellus poederi is morphologically charac- µm (8 collections), Qav. = 2.56–3.17, fusiform, smooth with obtuse apex, with a distinct suprahilar depression, not amyloid terised by its small size, the reddish cylindrical fusiform long nor dextrinoid, containing 1–3 lipidic globose drops or one el- stem in relation to the cap diameter, the dark reddish context in lipsoid drop filling almost the entire spore volume; under the the lower part of the stipe and by fruiting isolated to gregarious SEM spores lack any ornamentation. Basidia 4-spored, 33–45 on acid soil under Quercus robur. × 9–13 µm, sterigmata up to 5 µm in height, clavate, hyaline. In our ITS phylogeny (MycoBank supplementary data) Xero­ Pleurocystidia numerous, fusiform, with obtuse apex, 33–55 × comellus poederi is closely related to X. chrysenteron, X. poro­ 8–12 µm, hyaline, sometimes with yellowish content. Cheilo­ sporus and X. sarnarii, and to a lesser degree to X. dryophilus, cystidia similar to pleurocystidia. Caulohymenium throughout all of them belonging to the difficult X. chrysenteron complex the stem consisting of basidia, basidioles and cystidia similar (Peintner et al. 2003). The whole is strikingly different to those present in the hymenium. Pileipellis a trichodermium from Xerocomus and other taxa. Xerocomellus chrysenteron consisting of septate hyphae, the cylindrical cells of the hyphae differs from X. poederi because of its more robust habit and with thick walls, terminal cells very variable in shape, cylindrical its differently coloured stem context, with greenish to yellowish (narrower than lower cells) to lageniform, 30–40 × 9–11 µm, green tinges in the base, never dark reddish, and also because with abundant yellowish pigment forming patches or strips. of its association with or Fagus in Southern Europe. Clamp-connections not seen. Xerocomellus porosporus differs from X. poederi because of Habit, Habitat & Distribution — Growing solitary to gregari- the dark brownish colours lacking dark reddish tinges in the ous on acid soil under Quercus robur. Very abundant in the context at the base of the stem, as well as its apically truncate studied area. spores with a distinct germ pore. Xerocomellus dryophilus, a species described by Thiers (1975) from California, resembles Typus. Spain, Lugo, Parque Río Rato, Concello de Lugo, in humus of X. poederi because of the dark reddish context at the base of Quercus robur, 1 Nov. 2013, G. Moreno & J.M. Traba (holotype AH 44050, the stem, a feature which led many authors to confuse both taxa ITS sequence GenBank KU355475, LSU sequence GenBank KU355488, MycoBank MB815475). (Simonini 1994, Pérez de Gregorio 1995, Ladurner & Simonini 2003); however, it differs from X. poederi because of its larger Additional specimens examined. : Spain, Lugo, Xerocomellus poederi habit, the short stem in relation with the cap diameter, and a Parque Río Rato, Concello de Lugo, in humus of Quercus robur, 1 Nov. 2013, G. Moreno & J.M. Traba, paratype AH 44051 (ITS, LSU sequences strict association to Quercus agrifolia (coast Live ) (Bessette GenBank, KU355476, KU355489); idem, paratype AH 44052 (ITS, LSU et al. 2000, Desjardin et al. 2015). Xerocomellus sarnarii, a species described recently by Ariyawansa et al. (2015) from Italy, is macroscopically similar to X. poederi; however, it differs Colour illustrations. Spain, Parque Río Rato, Quercus robur forest, where from X. poederi because of its spores which have a small trun- the holotype was collected; basidiomata and fruit body section, trichodermium cature at the apex and a strict association with Mediterranean showing its variability, 4-spored basidium, hymenial cystidia, basidiospores, sclerophilous forests of Quercus ilex and Q. suber. smooth spores under SEM (holotype AH 44050). Scale bars = 1 cm (basidio­ mata), 10 µm (pileipellis, basidium, pleurocystidia, spores under LM), 2 µm For the description of the colours the Munsell soil colour charts (spores under SEM). were used (Munsell 1994).

Gabriel Moreno, Michel Heykoop, Fernando Esteve-Raventós, Departamento de Ciencias de la Vida (Área de Botánica), Universidad de Alcalá, E-28805 Alcalá de Henares, Madrid, Spain; e-mail: [email protected], [email protected], [email protected] Pablo Alvarado, ALVALAB, La Rochela n° 47, E-39012, Santander, Spain; [email protected] José María Traba, Plaza de España 1, E 15001 A Coruña, Spain; [email protected]

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