Cerrena multipileata

Regio, Nicolas Do Carmo, Westphalen, Mauro C. & Silveira, Rosa Mara Borges Da, 2024, Studies on Neotropical Cerrenaceae (Basidiomycota, Polyporales): a new species of Irpiciporus from Brazil, Phytotaxa 675 (3), pp. 217-232 : 227-228

Cerrena multipileata (Log.-Leite & J.E. Wright) Miettinen Fig.6

≡ Antrodiella multipileata C.L. Leite & J.E. Wright, Mycotaxon 41 (1): 167 (1991)

Mycobank: MB 849643.

Diagnosis:— Cerrena multipileata is characterized by the effused-reflexed basidiomes with imbricate pilei and presence of inconspicuous leptocystidia.

Description:— Basidiomes annual, effuse-reflexed, composed of an effused base and several laterally fused and imbricate pilei; pilei dimidiate, up to 3 cm wide and 3 mm thick. Pileus surface smooth, faintly zonate, white to cream-colored. Pore surface poroid to irpicoid, cream-colored, becoming pale brown to straw-colored after drying; pores mostly angular and irregular, often split and decurrent in resupinate parts of the basidiome, 2–5 per mm, tubes up to 2 mm deep, concolorous with the pore surface. Sterile margin very thin to absent, up to 1 mm wide, somewhat rounded, incurved after dried. Context thin, white to cream, homogenous, up to 1 mm thick.

Hyphal system dimitic. Generative hyphae clamped, hyaline, mostly thin-walled in the trama and subhymenium and thick-walled in the context, 2–5µm wide, several transitory hyphae observed (thick-walled hyphae with clamps), becoming more prominently thick-walled after the septum. Skeletal hyphae hyaline, thick-walled to solid, somewhat sinuous and mostly unbranched, 3–5 µm wide. Leptocystidia present, thin-walled, smooth, hyaline, usually scarce and inconspicuous, up to 5 µm and 6 µm wide, forming in the subhymenium and projecting among the basidia, staining strongly in Cotton Blue. Basidia clavate, tetraspored, hyaline, 12–16 × 3–4.5 µm. Basidiospores ellipsoid, hyaline, thin-walled, acyanophylous, IKI-, 3.5–4.4 × 2.4–3.2 µm.

Comments:—Morphologically, C. multipileata is very similar to C. zonata (Berk.) H.S. Yuan (2013: 363) but the latter can be distinguished by the darker ochraceous to buff pileus surface and the larger basidiospores (4.5) 5–6 × (2.5) 3–3.5 µm ( Núñez & Ryvarden 2001). In our molecular analysis, the Brazilian sequences nested in a sister clade slightly separated from the lineages from Central America, provided by Miettinen et al. (2023). Moreover, C. multipileata forms a strongly supported clade along with C. zonata and C. albocinnamomea (Y.C. Dai & Niemelä) H.S. Yuan (2014: 362) .

In the original description of Antrodiella multipileata , the authors referred to the cystidia as absent. However, leptocystidia can be seen among the basidia, but some can be small and inconspicuous, which may cause confusion. The presence of cystidia, of thick-walled generative hyphae, the size and shape of the basidiospores and the irregular hymenophore also support the placement of this species in Cerrena . However, the differences among Antrodiella and Cerrena may be subtle and the main morphological character that separates both genera is the presence of thin-walled cystidia in the latter, while in Antrodiella they are absent and only small cystidioles can be found in the hymenium.

Ecology and Distribution:—Growing on dead trunks of unidentified angiosperms. Known from southern Brazil, Argentina, Costa Rica and Guatemala ( Mata et al. 2007, Miettinen et al. 2023).

Specimens examined:— BRAZIL. Rio Grande do Sul, São Francisco de Paula , FLONA, 24 March 2007, L. V. Graf 349 ; ibid. 14 May 2018, M.C. Westphalen 650/18 (SP) ; ibid., 9 April 2022, N.C. Regio NR39 ( ICN). Santa Catarina, Florianópolis, Morro da Lagoa da Conceição , 26 July 1988, C.L. Leite & J. Furlani 195 and 223 ( FLOR, paratypes) ; ibid 27 July 1988, C.L. Leite & J. Furlani 251 ( FLOR!, holotype) ; São Martinho , 18 February 2005, J. Michels & J.M. Baltazar 439 ( FLOR) .

Figures

FIGURE 6. Cerrena multipileata (NR39). A. Basidiomes; B. Hymenophore configuration C–D. Leptocystidia. Scale bars: A = 2 cm; B = 1 mm; C–D = 10 µm. Photos: Mauro Westphalen (B, C and D) and Nicolas Regio (A).