Sistotrema bulbilliferum G.G. Barreto & Gusmão, 2023

Barreto, Gabriel G., Cantillo, Taimy, Costa-Rezende, Diogo H. & Gusmão, Luis F. P., 2023, A new bulbil-forming species of Sistotrema (Cantharellales, Hydnaceae) from Brazil, Phytotaxa 626 (1), pp. 8-20 : 15

Sistotrema bulbilliferum G.G. Barreto & Gusmão sp. nov. ( Fig. 2 )

Type:— BRAZIL. São Paulo: Rio Claro, Floresta Estadual Edmundo Navarro de Andrade ( FEENA), 22°24’51.9”S, 47°31’02.8’’W , dead bark of Eucalyptus grandis , 4 October 2019, G. G . Barreto (holotype: HUEFS 267156 (permanent slides); ex-type culture: CCMB 737 ; MB 850079 ) .

Etymology:— In reference to the production of bulbils.

Colonies developing over dead bark appearing as numerous spherical structures attached to the substrate by a rhizomorph-like mycelium, composed of hyaline, thin-walled, septate hyphae (2–4 µm wide), with numerous clamp connections. Bulbils roundish to ellipsoid, irregular (67–123 × 70–113 µm diam.), dispersed on substrate, hyaline to pale brown when young, brownish ochraceous when mature, externally smooth, appearing as an agglomeration of globose to irregularly angular cells, pseudoparenchymatous, swollen, smooth. No spores observed. Teleomorph unknown.

Notes:— Within Sistotrema , S. brinkmannii (Bres.) J. Erikss. (1948: 134) and S. oblongisporum M.P. Christ. & Hauerslev (1960: 82) are known to produce small nodules formed on mycelium. However, the capacity to produce bulbils is known to occur only in S. coronilla ( Hallenberg 1984) . Bulbils of S. coronilla are smaller (50–90 µm diam.), with cell walls densely clustered whereas in S. bulbilliferum bulbils are larger and the cell walls slightly loose. The phylogenetic analysis reveals that S. bulbilliferum forms a distinct lineage within Sistotrema s. l., related to S. coronilla and S. hypogaeum , but for the latter there is no record in the literature of it producing bulbils.

Figures

FIGURE 2. Sistotrema bulbilliferum. A. Bulbils in natural substrate.B. Colonies on CMCA (reverse). C–F. Bulbils. G. Hyphae with clamp connections. H. Bulbils developing in natural substrate attached to the hyphae. Scale bars:A = 0.5 mm, C–F, H = 50 μm, G = 20 μm.