Xylodon ramicida – Facesoffungi number: FoF 1006

Xylodon ramicida Spirin & Miettinen

MycoBank number: MB 813990 Facesoffungi number: FoF01006

Holotype: Spirin 7664

Etymology: Branch killer, derived from ramus (Lat.), branch

Basidiocarps annual, resupinate, arid, covering several cm. Sterile margin first white, floccose, up to 1 mm wide, absentin older basidiocarps. Hymenial surface pale ochraceous, odontoid; spines solitary or fused together, rather regularly arranged, up to 0.6 mm long, (3)4–5 per mm, with sharpened fimbriate apices. Hyphal structure monomitic, hyphae clamped, faintly cyanophilous. Subicular hyphae densely and mostly irregularly arranged, some in parallel bundles, with thickened walls, (2.8)3.1–3.8(4.3) μm( n=40/2). Tramal hyphae subparallel, thin- to slightly thick-walled, in subhymenium short-celled, (2)2.4–3(3.4) μm( n=40/2). Cystidia of hymenial origin, variable in shape and size, moniliform or capitate to bottle-shaped, (13)19.2– 31.3(34.8)×(3)3.1–4(4.7) μm( n=20/2), accidentally encrusted by small crystalline aggregations. Basidia suburniform, 4-spored, 18–23.6×3.6–4.6 μm, with thickened wall at basal part. Basidiospores thin-walled, cylindrical, often tapering to distal end, (6)6.1– 7.8(8.1)×(2.4)2.5–3(3.1) μm, L=6.66, W=2.74, Q=2.41– 2.48 (n=90/3), ventral side flat or indistinctly convex, very rarely slightly concave, occasionally with several oil drops. Oily matter scanty or absent.

Notes: Morphology and DNA data place X. ramicida in the vicinity of X. quercinus (Pers.) Gray, the type species of Xylodon. ITS sequence difference is only 5–7 bp. They have similar macroscopic characters and hyphal structure, but basidiospores of X. quercinus are wider, thick cylindrical, and often with a depressed ventral side, (5.6)5.7–7.5(7.6)×(2.7)2.8–3.3(3.4) μm, L=6.53, W=3.07, Q=2.06–2.18 (n=90/3). Moreover, tissues of X. quercinus exude abundant oily matter in Cotton Blue. Ecology and distribution areas of these species are different as well. Xylodon quercinus is found in Europe and Siberia, and it inhabits thick, dead and usually fallen branches of angiosperm trees, mostly of Quercus spp. It has not been reported from China, Japan, or Russian Far East (Langer 1994; Dai 2011). Xylodon ramicida is an East Asian species. It attacks living or dying but still attached branches of gymnosperms (mostly Picea ajanensis). A few records of X. ramicida come from living stems of Pinus pumila, the shrub-like pine species, thus indicating its possible pathogenic facilities. Xylodon quercinus has been reported from North America, but these data should be rechecked (Langer 1994).

Material examined: Xylodon quercinus: FINLAND, Uusimaa: Vantaa, Tammisto Nat Res., Quercus robur,1 June 2013 Niemelä9040(H).Uusimaa,Helsinki,Patola,Salix caprea (?), 2 November 2011 Miettinen 15050.1 (H), INSD KT361632. RUSSIA, Krasnoyarsk Reg.: Turukhansk Dist. Mirnoe, Alnus sibirica, 19 August 2013 Kotiranta 26316 (H). Nizhny Novgorod Reg.: Lukoyanov Dist., Razino, Q. robur, 8 September 2011 Spirin 4482 (H). Xylodon ramicida. RUSSIA. Khabarovsk Reg.: Solnechnyi Dist., Igdomi, Abies nephrolepis (fallen log), 6 August 2011 Spirin 3851 (H); Verkhnebureinskii Dist., Kyvyty, Picea ajanensis (attached branches), 17 August 2014 Spirin 7390,7469 (H), Hegdy, P. ajanensis (attached branches), 18 August 2014 Spirin 7482, 7505, 7518 (H), 22 August 2014 Spirin 7797 (H), A. nephrolepis (attached branch), 18 August 2014 Spirin 7536 (H), Pinus pumila (living stem), 22 August 2014 Spirin 7856 (H), Dublikan Nat Res., P. ajanensis (attached branches), 19–21 August 2014 Spirin 7583, 7635, 7664 (H, holotype, INSD KT361634), 7715, 7724, 7753 (H), 23 August 2014 Spirin7904(H), P.pumila(livingstem), 21 August 2014 Spirin 7764 (H), Sidorka, Picea obovata (attached branch), 24. VIII.2014 Spirin 7961 (H).