Lentaria gossypina R. Salas-Lizana, M. Villegas & E. Pérez-Pazos, sp. nov.

Index Fungorum number: IF 828900; MycoBank number: MB 828900; Facesoffungi number: FoF 05497; Figs. 1, 2

Etymology – From Latin gossypium, referring to the cottony mycelium that covers the stipe and basidiocarp branches.

Holotype – FCME 27625.

Basidiocarps solitary, gregarious or caespitose, annual, 20–150 mm long. Subiculum superficial over the substrates, extensive, white, plushy or cottony, with numerous whitish mycelial chords 1–2 mm thick. Stipe 10–30×2–10 mm, cylindrical to fattened, greyish orange, brownish orange to light brown (5B3, 5C4–6D4). Branches with four to five levels, predominantly dichotomous, fattened to sub-cylindrical, with internode length decreasing gradually towards the apex, parallel to semi-loose, greyish orange to light brown (5B4, 6D5) with light reddish brown tones (7/4 2.5Y), internodes rounded to sub-acute; surface covered irregularly with a thin layer of whitish mycelium, giving a cottony-tomentose appearance. Apices sub-rounded to acute, white, yellowish white, orange-white or light brown (4A2, 5A2, 5D5). Leathery, easily broken when dried; concolor context to the surface. Smell slightly sweet, astringent favor. Hyphal system monomitic, hyphae with thickened walls and conspicuous fbulae; occasionally ampulliform up to 12 μm wide. Subiculum and mycelial chords with 1–4 μm wide hyphae, covered with numerous crystals, irregular in shape and easily detachable. Branch context with 3.5–10 μm wide hyphae and some H connections. Hymenium thickened, amphigenous; basidia sub-claviform, hyaline, tetrasporic, sterigmata 2–10 μm long, with fbulae at the base, homogeneous content, 28–48×6–8.5 μm. Spores sub-sigmoid, smooth, thin-walled, (8–)9.3–12(13.5)×2.5–3.5 μm, L=11.5 μm, W=2.3 μm, Q=3.9 μm (n=30/1), which kept together in groups of two to four once detached from the sterigma.

Habitat and distribution – Lignicolous, mostly growing on highly rotten wood, producing white rot, sometimes developing on leaves or thorns of dead plants. Developing in subperennial and perennial forests, alt. 200 m.

Material examined – MEXICO, Campeche, Calakmul municipality, Escárcega-Chetumal highroad, Km 25 along the exit to the archaeological remains of Calakmul, 18o 18′02″ N, 89o 50′47″ W, 22 September 2003, VillegasRíos M. 2389 (FCME 27623); Chiapas, Tumbalá municipality, Cascadas de Bolo Naháu, 13 July 2010, Garibay-Orijel 2010–51 (FCME 27621); Tabasco, Macuspana municipality, Parque Estatal Agua Blanca 17°38′30″ N, 92°27′18″ W, 3 September 2007, González Ávila 75 (FCME 27620); Veracruz, San Andrés Tuxtla municipality, Estación de Biología de Los Tuxtlas, Circuito 1 pathway, 18º35′0.174″ N, 95º4′25.8″ W, 13 September 2010, Villegas- Ríos M. 2749 (FCME 27624); ibid. 28 August 2011, Villegas-Ríos M. 2796 (FCME 27625, holotype); ibid. 25 August 2012, Villegas-Ríos M. 2854 (FCME 27627); ibid. Villegas-Ríos M.2855 (FCME 27628); EL Vigia 1 pathway, 17 September 2011, Villegas-Ríos M. 2820 (FCME 27626); ibid. 28 July 2013, Ramírez-López I. 2013–14 (FCME 27622).

GenBank numbers – ITS: MK253203, MK253201, MK253195, MK253198, MK253199, MK253202, MK253197, MK253200, MK253196; LSU: MK253212, MK253204, MK253218, MK253219, MK253221, MK253220, MK253209).

Notes – The phylogenetic analyses of concatenated ITSLSU sequences place the new species in a well-supported monophyletic group, independent from any other species sequenced so far (Fig. 89). This species is diferent from all the tropical Lentaria species described so far on account of a very well-developed subiculum over the substrate, with the mycelium extending over the basidiocarp surface, giving a tomentose to cottony appearance. Additional observations showed that developing basidiocarps of L. gossypina form more mycelium or new basidiocarps when they touch the surface of a substrate. Spore size range is similar to that of L. bambusina P. Zhang & Zuo H. Chen (9.0–13×2.5–3.5 μm), whose stipe is also covered with a plushy layer of mycelium. However, L. bambusina has a smaller basidiocarp size (20–60 mm), diferent color (cinnamon brown) and the habitat is dead leaves of bamboo plants.

Figure 1 –  Majority-rule consensus tree of Lentaria gossypina, L. variabilis and reference sequences using a ITS and LSU concatenated matrix. Bayesian posterior probabilities (PP)≥0.84 and bootstrap support values (ML)≥70% are labeled. Type material for the new species are in bold. Outgroups are Dyctiophora rubrovolvata and Clathrus ruber

Figure 2 –  Basidiocarps of Lentaria gossypina (Pictures, Ramírez-López I.). a (FCME 27622). b (FCME 2796, holotype). Microscopic structures (FCME 2796, holotype). c Basidiospores. d Subiculum hyphae. Scale bars: a–b=10 mm, c–d=1 μm