Clavulina grisea Meiras-Ottoni & Gibertoni

MycoBank number: MB 818101 Facesoffungi number: FoF 2955

Etymology: grisea (Greek) = greyish, referring to the colour of the basidiomata.

Holotype: URM 89967

Basidiomata weakly branched or simple, solitary or in small groups, 2.5–8 cm, branches polychotomous, tips unique or bifurcated to cristae, consistency fleshy when fresh, brittle to crumbling when dry, grey to brownish-grey (5C1, 5C2, 5D1) when fresh, stipe well to not delimited 1–2.3 cm, white, beige to light brown (6A1, 6E3, 6E4) when fresh, young specimens white turning ochraceus (5A1, 5C3, 5C4) towards the apex of the branches, hymenium amphigenous developing just below the branching point and extending to the apex of the branches. Basidiospores globose to subglobose, 5.5‒8 (L = 6.63) × 4–6.5 (W = 5.67) μm, Q = 1.18, smooth, hyaline in water, pale yellowish in KOH 3%, with one large oleiferous guttule, thin-walled, with short apiculus (0.7–1 μm), IKI-. Hyphal system monomitic, tramal hyphae smooth, parallel, hyaline, 2–10 μm, slightly inflated, clamp connections abundant, subhymenium tightly interwoven. Cystidia hymenial hyaline, cylindrical with homogeneous to granular cytoplasmic contents, 85–98 × 5, 5–10 μm, no clamp connection at the base. Basidia elongate-clavate, approximately 31 × 5.5‒6 μm, hyaline, guttulate, with 2 cornute sterigmata, 4–6 μm, clamped at the base, but agglutinated and difficult to observe.

Material examined: BRAZIL, Acre: Sena Madureira, Floresta Nacional de São Francisco, January 2015, A. Meiras-Ottoni & S.O. Almeida (URM 89966); BRAZIL, Acre: Sena Madureira, Reserva Extrativista Cazumbá-Iracema, January 2015, A. Meiras-Ottoni & S.O. Almeida (URM 89967, holotype; isotype in O); BRAZIL, Acre: Sena Madureira, Reserva Extrativista Cazumbá-Iracema, January 2015, A. Meiras-Ottoni & S.O. Almeida (URM 89968, paratype). GenBank numbers URM 89967 ITS:KX811199, URM 89968 ITS:KX811184.

Notes: This species is characterized by the slender, flexible, fleshy and greyish basidiomata when fresh, brittle when dry, and by the hymenial, hyaline cystidia with homogeneous to granular contents. Clavulina grisea composed of several solitary basidiomata growing on soil covered by rotten leaves and branches.

Other species of Clavulina with greyish basidiomata and cystidia have been reported by Corner (1956, 1970) and Petersen (1983). Clavulina hispidulosa Corner, however, has subhyaline to pale yellow or pale brownish, subglobose to obovoid, larger basidiospores (8‒12 × 7–10.5 μm), while C. griseopurpurascens Corner has hyaline, usually ellipsoid basidiospores (7.5–8.7 × 6‒7 μm).

Phylogenetic tree of the Clavulina obtained by analyses from rDNA sequences. Taxa with two accession numbers were analysed by concatenated ITS and partial LSU rDNA; both regions ITS and partial LSU rDNA was used to analyse the other individuals. Support values (from top) are maximum likelihood, maximum parsimony and Bayesian analyses. Sequences obtained in this study are in boldface. Only support values of at least 50% are shown. The tree was rooted with Hydnum albomagnum, H. repandum and H. umbilicatum.


Clavulina grisea (URM 89967, holotype). a, b Basidiomata. c Hyphae with clamps (KOH). d Basidiospores with apiculus (KOH). e Cystidia (in Melzer’s reagent). Scale bars: a, b = 5 cm, c-e = 10 µm.