Gelacantha pura V. Malysheva & V. Spirin, in Spirin et al., Nordic Journal of Botany 37: 8 (2019)
Etymology: Purus (Lat., adj.) – pure.
Diagnosis: Basidiocarps semitranslucent, effused, continuous, gelatinous, whitish, adnate, drying to a glittering vernicose crust; hymenophore smooth or hydnoid, spines irregularly spread over hymenial surface, acute, up to 150 × 100 μm, often fusing together; subiculum up to 0.1 mm thick, almost invisible in dry condition; margin indistinct; mineral inclusions absent
Hyphal structure monomitic; hyphae clamped, interwoven, subicular hyphae slightly thick-walled, 4–5 μm in diam., subhymenial hyphae thin-walled, 2–3 μm in diam. Cystidia absent; hyphidia abundant, simple to branched, 2–3 μm in diam. at the apical part. Basidia 2–4-celled, (9.2–) 9.8–11.8 (–12.0) × (8.2–) 8.3–10.1 (–10.2) μm (n = 20/1), openly arranged, sometimes obliquely septate; enucleate stalk up to 14 × 4.5 μm, of equal width along the whole length or gradually widening toward apical cells; sterigmata up to 11 × 2.5–4 μm. Basidiospores ellipsoid to ovoid, rarely cylindrical, (5.2–) 5.7–7.2 (–7.3) × (4.1–) 4.2–5.8 (–6.0) μm (n = 30/1), L = 6.45, W = 5.06, Q = 1.28.
Distribution and ecology: Europe (Russian Caucasus); fallen log of Abies. So far known from the type locality only
Index Fungorum number: IF829006
Notes: Sparsely and irregularly distributed spines make G. pura different from the similar-looking Protodontia subgelatinosa and Protoacia delicata. The latter species, also occurring on coniferous hosts, has shorter, more globose basidiospores (versus ellipsoid-ovoid in G. pura).
Figure 1. Combined phylogenetic nrITS+nrLSU topology from maximum likelihood analysis showing main lineages within Auriculariales. All sequences generated for this study are indicated in bold faces. Collection numbers of specimens are given for all sequences. Full red circle indicates clades that include taxa with sphaeropedunculate basidia (empty circle indicates absence of this feature). Support values (ML/BA) are given above the branches. Scale bar shows expected changes per site.