Subulicystidium harpagum Ordynets, M.M.Striegel & 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 harpagum Ordynets, M.M.Striegel & K.H.Larss. sp. nov. Figs 7a, b ; 10r

Diagnosis.

Differs from other Subulicystidium species by the cystidia which resemble a harpoon due to protruded backward pointing individual crystals and moderately large cylindric to allantoid basidiospores (5.7-8.2 × 2.2-3.0 µm).

Type.

RÉUNION. Saint-Pierre : Saint-Philippe, Forêt de Mare Longue, 495 m, -21.3438, 55.7410, on dead tree branch, 28 Mar 2015, M.Striegel (L 1726a in FR, isotype in KAS) .

Etymology.

harpagum, from the Latin “harpaga”, English “harpoon”, a spear with barbs and serrated edges used in fishing. Epithet refers to the cystidium encrustation pattern.

Description.

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

system monomitic. All septa with clamps. Subiculum thin, with interwoven richly branched hyphae 2-3 µm wide, thin-walled to very slightly thick-walled, hyaline, often with rough surface because of slight encrustation. In the older fruit-body parts, encrustation represents an up to 1 µm thick sheath over the hypha. Subhymenium thin, with hyphae identical to those in subiculum. Cystidia subulate, 35-62 × 2.5-3.5 µm including encrustation, projecting up to 30 µm, without basal swelling, terminal or pleural, with thin to slightly thickened hyaline cell wall and outer hyaline crystal sheath covering the whole cystidium except the thin-walled, acuminate and particularly narrow, apex. Crystal protrusions on cystidium are formed like short rods that project backwards under acute angle, thus making cystidia resembling a harpoon.

Basidia suburniform, 9-12 × 4.2-5.7 µm, thin-walled, with 4 sterigmata and a basal clamp, basally slightly encrusted. Basidiospores weakly allantoid, adaxial side concave, L=(4.5-)5.7-8.2(-8.7) µm, W=(2.0-)2.2-3.0(-3.3) µm, Q=(1.7-)2.1-3.4(-3.8), N=178/4, with minute apiculus, smooth, thin-walled, hyaline, often with two oil drops (one at each pole), negative in Melzer’s reagent. Tolerance limits for basidiospore length, width and length to width ratio in S. harpagum based on 4 sequenced specimens are provided in Table 2 .

Additional specimens examined.

RÉUNION. Saint-Benoît: Sainte-Rose, Foret de Bois Blanc , 640 m, -21.2081, 55.7981, on strongly decayed wood, 21 Mar 2013, E.Langer (L 0244 in FR and KAS) . JAMAICA. Cornwall County: Trelawny parish, Windsor Cave, along trail to Troy , 18.3564, -77.6472, on twig of angiosperm tree, 12 Jun 1999, K.-H.Larsson ( KHL 10733 in GB) . COLOMBIA. Magdalena: Parque Nacional Tayrona, Estacion de Gairaca , 0-30 m, 11.3170, -74.1063, on dead twig, 12 Jun 1978, L.Ryvarden (LR 15736 in O:F) .

Remarks on species.

The holotype specimen contains also a small piece of S. perlongisporum , now kept in a separate clearly labelled envelope within the voucher. Despite being mixed, the specimen was still selected as type because of the hymenium and subhymenium are better preserved and the ITS and 28S sequences retrieved are of higher quality.

Figures

Figure 7. Species of Subulicystidium with smallest cylindric basidiospores. Subulicystidium harpagum (KAS: L 1726 a, holotype): a cystidia b basidiospores. Subulicystidium parvisporum (KAS: L 0140, holotype): c basidiospores d cross sections through fruit-body. Preparations a, b, c done in 3 % aqueous solution of potassium hydroxide (KOH) mixed with 1 % aqueous solution of Phloxine, preparation d simply in KOH. 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.