Subulicystidium oberwinkleri Ordynets, Riebesehl & K.H.Larss., 2018

Ordynets, Alexander, Scherf, David, Pansegrau, Felix, Denecke, Jonathan, Lysenko, Ludmila, Larsson, Karl-Henrik & Langer, Ewald, 2018, Short-spored Subulicystidium (Trechisporales, Basidiomycota): high morphological diversity and only partly clear species boundaries, MycoKeys 35, pp. 41-99 : 41

Subulicystidium oberwinkleri Ordynets, Riebesehl & K.H.Larss. sp. nov. Figs 5a, b ; 10t

Diagnosis.

differs from Subulicystidium nikau (G. Cunn.) Jülich by having plate-like to irregular crystals on cystidium and longer basidiospores (7.8-10.8 µm long).

Type.

RÉUNION. Saint-Pierre : Saint-Philippe, Forêt de Mare Longue, 495 m, -21.3438, 55.7410, on dead woody branch, 28 Mar 2015, J.Riebesehl (L 1860 in FR; isotype in KAS) .

Etymology.

oberwinkleri, named after Franz Oberwinkler, a German mycologist who provided a perceptive view into the species concepts in Subulicystidium and was an early collector of the species in South America.

Description.

Basidiomata annual, effused, resupinate, soft and fragile, arachnoid, loosely adnate and easily separable. Hymenophore smooth, velutinous due to numerous protruding large cystidia, porulose, whitish to yellow. Margin abrupt, not differentiated.

system monomitic. All septa with clamps. Subiculum with interwoven and richly branched hyphae 3-4 µm wide, occasionally swollen up to 6 µm, slightly to moderately thick-walled, hyaline. Subhymenium thin and loose. Subhymenial hyphae richly branched, intricate, regular or occasionally slightly inflated, 3-4 µm wide, thin-walled. Cystidia tubular, 80-150 × 5.5-10 µm including encrustation, projecting up to 70 µm, without basal swelling, with septa having or devoid of clamps, with thin or only slightly thickened hyaline cell wall and outer hyaline crystalline sheath (up to 3.5 µm thick) covering at least the lower half and, at a maximum, almost the whole cystidium except the short, 2-3 µm wide, hyphoid, cylindrical or tapering apex. The crystal protrusions on cystidium are large, plate-like, slightly rhomboid or irregular in outline, somewhat imbricately arranged. Similar encrustation pattern is found also on the subicular and especially subhymenial hyphae and sometimes on the bases of basidia.

Basidia suburniform to urniform, 12-18 × 6-8 µm, thin-walled, with 4 sterigmata and a basal clamp, terminal or sometimes pleural. Basidiospores broad cylindric to reniform, adaxial side slightly concave, L=(7.4-)7.8-10.8(-11.6) µm, W=(3.7-)4.0-5.5(-5.8) µm, Q=(1.6-)1.6-2.3(-2.4), N=99/3, with a prominent apiculus, smooth, thin-walled, hyaline, negative in Melzer’s reagent.

Additional specimens examined.

RÉUNION. Saint-Benoit: Saint-Benoit, Foret de Bebour , Bebour-I-87, Cryptomeria forest, 1200 m, on dead wood of Cryptomeria japonica , 24 May 1987, J.Boidin (LY 12488) . VENEZUELA. Estado Aragua: Maracay, National Park Henri Pittier , Rancho Grande , 10.3800, -67.6190, on dead wood, 30 Aug 1999, K.-H.Larsson ( KHL 11042 in GB). Estado Merida: La Carbonera, Road Merida-La Azulita, 2000-2200 m, on dead wood, 19 Jan 1969, F.Oberwinkler (FO 14338 in TUB) .

Remarks on species.

Specimens of S. oberwinkleri were noticed for the peculiar cystidia previously by Oberwinkler (1977) and later by Maekawa (1998). Neither author was prepared to assign them to a separate species and instead labelled them as S. nikau (characterised by regularly ornamented cystidia). Our examination of the specimens TUB:FO 14338 from Venezuela ( Oberwinkler 1977, fig. 31) and LY 12488 from Réunion ( Boidin and Gilles 1988, fig. 39A) showed that both represent S. oberwinkleri .

Figures

Figure 5. Species of Subulicystidium with broad cylindric basidiospores. Subulicystidium oberwinkleri (KAS: L 1860, holotype): a cystidia b basidiospores. Subulicystidium nikau (KAS: L 1296): c cystidia d basidiospores. Subulicystidium boidinii (KAS: L 1584 a, holotype): e mature hymenium f young hymenium g basidiospores. All preparations done in 3 % aqueous solution of potassium hydroxide (KOH) mixed with 1 % aqueous solution of Phloxine. All scale bars equal 10 µm.

Figure 10. Basidiospore shape and size in all studied species of Subulicystidium. Each species is illustrated by a single specimen and herbarium codes are indicated on the figure.