Neodictyopus atlanticae Palacio, Robledo & Drechsler-Santos

Pagin-Cláudio, Filipe & Gugliotta, Adriana de Mello, 2024, Six new records of polypores (Agaricomycetes, Basidiomycota) from Southeast Brazil (Atlantic Forest) and perspectives in basic mycological research, Rodriguesia (e 00672024) 76, pp. 1-15 : 7-8

5. Neodictyopus atlanticae Palacio, Robledo & Drechsler-Santos , in Palacio, Robledo, Reck, Grassi, Góes-Neto & Drechsler-Santos, PLoS ONE 12(10): e0186183, 15 (2017).

Figs. 6 a-c; 7a-f; 9f

Basidiomata pileate, seasonal to perennial, laterallytoeccentricallystipitate, widelyflabelliform, reniform, discoid to circular, coriaceous, gregarious in small groups, sometimes cespitose, 1.5–5.5 × 1.8–3 cm, up to 2.5 mm thick. Abhymenial surface azonate, glabrous, radially striate to occasionally radially rugose when dehydrated, orange-brown, reddish-brown, dark red to purple, often darker in the central region, usually with a depression. Stipe covered by a dark cuticle, insertion at 90° to 180°, up to 2.3 cm high, up to 0.8 mm in diam. - but rarely surpassing 0.5 mm, reticulate, glabrous to slightly pubescent, base radially extended in the substrate. Margin acute to subobtuse, frequently marked by a dark line, deflexed when dehydrated. Context fibrous to occasionally pubescent, cream to grayish-cream, eventually with resinous bands, 1–3 mm thick. Tubes with up to two layers, but often one, cream, grayish-cream to brownish, up to 1 mm each layer. Hymenial surface poroid, grayish-cream, puff gray, dark gray to dark brown. Pores hardly seen to the naked eye, round to angular, 5–9(–10) per mm. Dissepiments entire, granulose to pubescent, slightly to moderately thick. Hyphal system dimitic. Trama frequently impregnated by resinous yellowish-green substance. Generative hyphae frequent, with unilateral clamps, thin-walled, tortuous, densely branched, (1.5–)2–3(–6) μm diam. Skeletal-binding hyphae dominant, aseptate, hyaline, thick-walled to solid, very tortuous, densely branched, 1–4(–5) μm diam. Cystidioles frequent, widely fusiform to narrowly utriform, with basal clamp, (8.5–)12–16 × (3–)4.7–6.5(–8) μm. Cystidia absent. Basidia clavate, 4-sterigma, hyaline, 5 μm wide. Basidiospores rare to frequent, abundant only in pores, subcylindrical, hyaline, often with refringent and ferruginous content, 5–6.9(–7.5) × (1.8–)2–3(–4) μm, Lm × Wm 6.1 × 2.3 μm, Q = (2.1–)2.2-3(–3.1), Qm = 2.6, (n = 334/6).

Material examined: Juquitiba, São Paulo Green Belt Biosphere Reserve, Zé da Paz (Parcela ESALQ), 3.X.2021, F.Pagin, FP 461, SP 528795, F.Pagin 463, SP 528796; Chama Violeta, F. Pagin, FP 507, SP 528837; Chama Violeta, 13.VII.2022, F. Pagin et al. FP 520, SP 528849; Trilha da Jaguatirica, 13.IV.2022, F. Pagin et al. FP 543, SP 528871; Chama Violeta, 13.VII.2022, F. Pagin et al. FP 550, SP 528877; Trilha da Onça Parda, 22.IX.2022, F.Pagin et al. FP 579, SP 528905; Trilha da Jaguatirica, 24.XI.2022, F. Pagin et al. FP 598, SP 528924.

Xylophagous on angiosperm wood, the species causes white rot.

The species was found in Brazil ( Palacio et al. 2017). Previously recorded from the Brazilian Atlantic Forest in the state of Santa Catarina ( Palacio et al. 2017). This is the first record from the Southeast of Brazil.

The type locality of Neodictyopus atlanticae is Santo Amaro de Imperatriz , Santa Catarina, Brazil ( Palacio et al. 2017) .

Neodictyopus atlanticae can be recognized in the field by its pileate, laterally to eccentrically stipitate, leathery basidiomata, black cuticle covering the stipe, often reddish-orange to purple, radially striate abhymenial surface, grayish-cream to brown hymenial surface, as well as by pores which are hardly seen to the naked eye.

The potential geographic distribution presented in Palacio et al. (2017) shows that Picipes dictyopus (Mont.) B.K. Cui, Xing Ji & J.L. Zhou , a morphologically similar species, is distributed in the Cerrado province, as well as in Juan Fernandez Islands, where N. atlanticae is distributed in the Atlantic province.

We observed a case of polymorphism (see paragraph 4 of the discussion) in N. atlanticae ( Figs. 6-7 ) through morphological analysis of basidiomata. The morphological features - stipe, pileus and margin configuration as well as basidiospores size (value o Q) - used to distinguish between N. atlanticae (Atlantic province) and P. dictyopus (Cerrado province) ( Palacio et al. 2017) overlapped. We observed that phenotypic traits used to distinguish these taxa had low taxonomic value when more specimens were sampled. Firstly, the unknown specimens were morphologically chimeric, exhibiting mixed features used to distinguish N. atlanticae and P. dictyopus . Thus, for the identification of N. atlanticae we used the Q value of basidiospores by means of measurements from all sampled specimens (334 basidiospores/- 6 specimens).Accounting for one subpopulation, they had higher taxonomical value, which were equal to Q = 2−3.5 matching the original description of N. atlanticae (vs. Q = 2.5–3.3 in P. dictyopus ) ( Palacio et al. 2017; present study). Although, we lack molecular metadata for the material examined, morphological evidence supports the hypothesis that N. atlanticae occurs in the Atlantic province,while P. dictyopus is found in the Cerrado province in Brazil ( Palacio et al. 2017; present study).

Figures

Figure 6 – a-c. Neodictyopus atlanticae. Macromorphology of the basidiomata – a. basidiomata; b. inferior view of the basidioma; c. pores. (a-c. Pagin et al. 530). Scale bars: a-b = 1 cm; c = 1 mm.

Figure 7 – a-f. Polymorphism of Neodictyopus atlanticae. Superior and inferior views of the basidiomata. (a-b. Pagin et al. 507; c-d. Pagin et al. 543; e-f. Pagin et al. 550). Scale bars: a-f = 1 cm.