Tropicoporus stratificans G. Coelho & Yurchenko, 2016

Coelho, Gilberto, Silveira, Andressa De Oliveira, Antoniolli, Zaida Inês & Yurchenko, Eugene, 2016, Tropicoporus stratificans sp. nov. (Hymenochaetales, Basidiomycota) from southern Brazil, Phytotaxa 245 (2), pp. 144-152 : 147-149

Tropicoporus stratificans G. Coelho & Yurchenko , sp. nov. ( Figs. 2 and 3 )

MycoBank:—MB 811039

Diagnosis:— Basidioma perenne, resupinatum, primum simplex, deinde multistratosum; margine aureo-brunneo in juvenis, demum nigrescente, rimoso, stratificanti in senectute; hymenophoro cinnamomeo ad nigro-castaneum, aureo-nitenti luce reflexa; sistemate hypharum dimitico, hyphis sine fibulis; basidiosporis ellipsoideis, flavo-ochraceis ad ochraceo-ferrugineas, crassitunicatis; setis ventricosis ad lanceolatas, atro-ferrugineis, abundantibus. Holotypus SMDB 14730, crescit prerunque sub trunco putrescenti, in regione urbis Sanctae Mariae Colletato, Brasilia meridionali.

Etymology:— Stratificans (Latin) —referring to stratifying basidiomes

Basidiomes perennial, resupinate, up to 150 mm long × 75 mm wide, and 30 mm thick, firmly attached to the substratum, rarely with reflexed margins, wettish and somewhat heavy when fresh, becoming lighter upon drying. Hymenophore poroid; pore surface yellowish brown (5/4–5/8 10YR) to dark yellowish brown (4/4–3/6 10YR) when fresh, distinctly lighter when turned in incident light, in this case changing to yellow (8/6–7/8 10YR) and becoming similar to the margin; pores round, seldom elongated, sometimes irregular or polygonal, (4)5–7(8)/mm, P m = 5.57, n = 126/2; dissepiments delicately pilose, entire, sometimes lacerate with age; margin of pore layer usually adhering to the substratum, rarely lifted when mature, growing margin velutinous, well delimited, up to 4 mm broad, variable in width, brightly colored, yellow (8/6–7/8 10YR) to brownish yellow (6/6–6/8 10YR) when fresh, becoming hard,

rimose, stratified and zoned by accumulating successive sterile margins with age, very dark brown (2/2 10YR) to black

(2/1 10YR) with shades of dark brown (3/3 10YR). Context thin, up to 2 mm thick next to the substratum, absent or residual between pore layers, firm, woody. Tube layer concolorous with the pore surface, continuous, firm, but brittle when fresh, hard when dry, dull, simple or becoming stratified, strata up to 2 mm thick.

Hyphal system dimitic; tramal generative hyphae simple-septate, hyaline to pale yellow, thin- to slightly thick-walled, (1.5)2–3(3.5) μm in diam, D m = 2.5, n = 125/2; skeletal hyphae in trama ferruginous brown, slightly thinner than those from the context, (2.5)3–4(4.5) μm in diam, D m = 3.3, n = 124/2; generative hyphae in context simple-septate, hyaline to pale yellow, thin- to moderately thick-walled, (1.5)3–3.5(4.5) in diam, D m = 3.0, n = 124/2; skeletal hyphae in context predominating, ferruginous brown, moderately to very thick-walled, usually with a narrow lumen, (2.5)3–5(5.5) in diam, D m = 4.0, n = 124/2.

Hymenium of basidia, basidioles, cystidioles, and setae. Basidia short clavate, hyaline, (8)9.5–13.5(15) × (4.5)5– 7(7.5) μm, L m × W m = 11.0 ± 1.44 × 6.14 ± 0.70, Q r = 1.25–3.00, Q m = 1.82, n = 107/2. Basidiospores subglobose to ellipsoid, thick-walled, pale yellow when juvenile, predominantly ferruginous brown at maturity, especially those remaining in old tube layers, (3.5)4–5(6) × (3)3.5–4(4.5) μm, L m × W m = 4.50 ± 0.33 × 3.69 ± 0.25, Q r = 1.00–1.50, Q m = 1.22, n = 124/2. Setae ventricose to lanceolate, dark ferruginous brown, thick-walled, (12)17–30(45) × (3)4.5–7(9) μm, L m × W m = 24.8 ± 5.30 × 5.80 ± 1.05, Q r = 2.25–8.75, Q m = 4.43, n = 125/2, more abundant next to pore apertures, sometimes grouped, seldom rooted deep in trama, often incurved at base. Cystidioles usually present, mostly in fresh hymenia, hyaline, ventricose, inconspicuous.

Distribution:–Known from the extreme southern part of Brazil, in subtropical semideciduous forests, at 40–500

m a.s.l., on transitional lands from the Central Depression Region of Rio Grande do Sul State and southern border of the Brazilian Meridional Plateau.

Substratum:–Basidiomes usually occur on the underside of fallen trunks of undetermined angiosperms at different stages of decay, or rarely on living trees.

Remarks:—The main macroscopic diagnostic features of T. stratificans are the resupinate, perennial, multi-layered basidiomes that usually become distinctly hard at the margin due to superimposed darkened rimose layers. The main microscopic distinguishing features are the dimitic hyphal system, the dark ferruginous-brown hymenial setae (which are somewhat variable in form and size, and more abundant or grouped at the pore mouth), and subglobose to ellipsoid, thick-walled, ferruginous-brown basidiospores.

Type:— BRAZIL. Rio Grande do Sul State: Municipality of Santa Maria, 9 Nov 2011, G. Coelho (Holotype, SMDB 14730).

Paratype specimens:— BRAZIL. Rio Grande do Sul State: Municipality of Itaara , 18 Feb 1992, G. Coelho 11-5 ( ICN 97813 ) ; 1992, G. Coelho 23-1 ( ICN 97815 ), 23-2 ( ICN 97816 ) ; Municipality of Santa Maria, Água Boa , 4 Jul 2003, G. Coelho 394-8 ( SMDB 14737 ) ; Caturrita , 1992, G. Coelho 20-1 ( ICN 97814 ), 7 Jun 1993, G. Coelho 40-8 ( ICN 97818 ) ; 6 Dec 1993, G. Coelho 35-10 ( ICN 97817 ) ; Cerrito , 13 Jun 1993, G. Coelho 41-1 ( ICN 97819 ), 41-2 ( ICN 97820 ), 41-7 ( ICN 97821 ) ; 13 Sep 1993, G. Coelho 47-2 ( ICN 97822 ), 47-5 ( ICN 97823 ), 47-7 ( ICN 97824 ), 47- 10 ( ICN 97825 ) ; 20 Dec 1993, G. Coelho 51-5 ( ICN 97826 ) ; 9 Nov 2011, G. Coelho ( SMDB 14731 , 14732 ) ; 28 Feb 2013, G. Coelho ( SMDB 14738 , 14739 ) .

Additional specimen examined:— Sanghuangporus vaninii — RUSSIA, Khabarovsk Region, Bol’she- Khekhtsyrskii Reserve, Bychikha, 4 Sep 1979, E. Parmasto ( ICN 97827, ex TAA 102315, under the name Phellinus vaninii ).

Figures

FIGURE 2. Tropicoporus stratificans. A. Mature hymenophoral layer growing on older one (SMDB 14738). B. Margin detail of perennial basidiome (SMDB 14739). C. Microscopic details of dissepiment (SMDB 14730). D. Hymenophoral setae (SMDB 14730). E and F. Basidiospores (SMDB 14731).

FIGURE 3. Tropicoporus stratificans (SMDB 1544).A. Basidia. B. Basidiospores. C. Skeletal hyphae. D. Hymenial setae. E. Generative hyphae from trama.