Phellinotus neoaridus Drechsler-Santos & Robledo, 2016

Drechsler-Santos, Elisandro Ricardo, Robledo, Gerardo Lucio, Lima- Júnior, Nelson C., Malosso, Elaine, Reck, Mateus A., Gibertoni, Tatiana B., De Queiroz Cavalcanti, Maria A. & Rajchenberg, Mario, 2016, Phellinotus, a new neotropical genus in the Hymenochaetaceae (Basidiomycota, Hymenochaetales), Phytotaxa 261 (3), pp. 218-239 : 224-228

Phellinotus neoaridus Drechsler-Santos & Robledo sp. nov. ( Figs 2A–G , 3A, C, E , Table 2)

Typus:— BRAZIL. Pernambuco: Serra Talhada, Estação Experimental do IPA, on living caatingueira tree ( Caesalpinia sp. ), 7º53’29” S, 38º18’17” W ‒ 490m alt., 09 December 2008, Drechsler-Santos DS105PE (holotype URM 80362, isotype FLOR 53152).

Mycobank no:—MB805901

Etymology:— neoaridus , in reference to the neotropical semiarid region of Brazil covered by Caatinga, a seasonally dry forest of the SDTFs biome ( Särkinen et al. 2011), where the species was first encountered.

Diagnosis:—Basidioma pileate, annual to perennial, distinctly rimose; black lines near the upper surface of the pileus present; tubes distinctly stratified, hymenophore poroid (3‒6/mm). Hyphal system dimitic with skeletal hyphae restricted to trama of tube layer. Basidiospores ellipsoid (5‒7 × 4‒5.5 μm), adaxially flattened, thick-walled, yellow, chestnut brown in KOH. Pathogenic on Caesalpinia spp .

Description: —Basidioma mostly perennial, more rarely annual to bi-annual, pileate, projecting up to 150 mm, 100 mm wide and 80 mm thick at base, first applanate, triquetrous to strongly ungulate with age, sometimes with a basal umbo; hard; usually solitary or in groups of several basidiomata widespread along the substrate; margin applanate to convex, always distinct from older parts, cream to ochre orange at first, then turning brown with age. Pileus variable in color, first cream to reddish yellow or olive to black, dull when rimose, azonate then sulcate, and finally strongly rimose. Context 11‒21 mm thick in young, 3‒5 mm thick in ungulate specimens, weakly zonate near the base to azonate towards the margin, with black lines near the upper surface of the pilei, granular core variably present, pale to dark brown, becoming black with KOH, a thick gray to black crust present above contex. Tubes stratified, dark reddish brown, without distinct tissue development between layers.

Hymenophore poroid, pores round, some elongated, 3‒6/mm, (90‒)150‒280(‒350) μm wide, reddish yellow to dark brown; dissepiments entire, (20‒)40‒150(‒300) μm wide. Hyphal system dimitic with skeletal hyphae restricted to the trama of the tube layer; contextual generative hyphae pale yellow to dark reddish brown, thin to thick-walled, lumen (3‒)4‒6(‒7) μm wide, regularly simple-septate with ramifications, then becoming sclerified and septa in some portions of thick-walled hyphae destroyed, sometimes forming secondary septa; trama of tube layer composed of generative simple-septate and skeletal hyphae; generative hyphae hyaline, pale yellow to fulvous, thin to thick-walled, (0.5‒)1‒2(‒3) μm wide, forming terminal, dark reddish brown skeletal hyphae, (110‒)232‒533(‒560) × (3‒)4‒6(‒7) μm, lumen absent to 1–1.5 μm wide, with 1–4 adventitious septa at the narrow to obtuse apex; granular core with few to many sclereoid hyphae. Basidia not observed. Basidiospores broadly ellipsoid to ellipsoid, 5‒6.5(‒7) × 4‒5(‒5.5) μm (ave. = 5.8 × 4.7 μm), Q = 1.2‒1.3 (ave.Q = 1.2), adaxially flattened, smooth, thick-walled, yellow, chestnut brown in KOH, weakly cyanophilous, IKI-.

Habitat and distribution:—Commonly found on living Caesalpinia spp . ( Fabaceae ) ( Drechsler-Santos et al. 2010, 2013, as P. rimosus ). Some basidiomata, mostly those that are annual or bi-annual, are found fallen on the ground near the tree where they presumably developed. Usually, ungulate specimens with many tube layers were found on the tree trunk as well. This species is widely distributed in the Brazilian semiarid region (Caatinga dry woodlands), from the states of Alagoas, Bahia, Ceará, Paraíba, Pernambuco, Rio Grande do Norte and Sergipe.

Remarks:—The typical triquetrous to ungulate basidiomata with a black rimose pileus and reddish brown hymenophore are useful in distinguishing this species. When present, the context of P. neoaridus is weakly zonate developing one or more dark lines below the rimose upper surface of the pileus and some basidiomata present a very distinct granular core. Phellinotus piptadeniae is similar, but develops a less rimose pilear surface, a distinct black line in the context, and smaller basidiospores. Additionally, it grows repeatedly on Piptadenia spp . ( Drechsler-Santos et al. 2010, 2013, as Phellinus rimosus ).

Material examined:— BRAZIL. Alagoas: São José da Tapera, Fazenda do Sr. Rudá, on living Caesalpinia sp. , 9º32’47” S, 37º33’11” W ‒ 227m alt., 17 June 2008, Drechsler-Santos & al DS017AL (URM 80411, O); ibid, on living Caesalpinia sp. , 9º32’49” S, 37º33’27” W ‒ 224m alt., 17 June 2008, Drechsler-Santos & al. DS009AL (URM 80579); ibid, on living Caesalpinia sp. , 9º32’49” S, 37º33’29” W ‒ 230m alt., 17 June 2008, Drechsler-Santos DS007AL (URM 80410). Ceará: Reriutaba, Serrote de Boqueirão on living Caesalpinia sp. , 4º01’13” S, 40º38’43” W ‒ 290m alt., 15 June 2007, Drechsler-Santos DS034CE (URM 80847); ibid, on living Caesalpinia sp. , 4º01’15” S, 40º38’41” W ‒ 280m alt., 15 June 2007, Drechsler-Santos DS033CE (URM 80536). Paraíba: Sumé, Fazenda Almas, on living Caesalpinia pyramidalis Tul. , 7º28’21” S, 36º53’28” W ‒ 686m alt., 10 August 2008, Drechsler-Santos & Rajchenberg DS044PE (URM 80494). Pernambuco: Cabrobó, Fazenda Mosquito, on living Caesalpinia sp. , 08º23’06’’ S, 39º25’30’’ W ‒ 75m alt., 21 November 2009, Robledo 1974 (CORD); Serra Talhada, Estação Experimental do IPA, on living Caesalpinia sp. 7 º53’49” S, 38º18’12” W ‒ 501m alt., 5 March 2009, Drechsler-Santos & al. DS143PE (URM 80769); ibid, on living Caesalpinia sp. , 7º53’50” S, 38º18’11” W ‒ 560m alt., 5 March 2009, Drechsler-Santos DS151PE (URM 80764); ibid, on living Caesalpinia sp. , 7º53’20” S, 38º18’25” W ‒ 486m alt., 11 March 2008, Drechsler-Santos DS056PE (URM 80641); ibid, on living Caesalpinia sp. , 7º53’47” S, 38º8’12” W ‒ 502m alt., 5 March 2009, Drechsler-Santos DS140PE (URM 80741); ibid, 7º55’78” S, 38º17’39” W ‒ 504m alt., 12 September 2007, Drechsler-Santos DS22PE (URM 80299, O). Sergipe: Niterói on living Caesalpinia sp. , 9º45’23” S, 37º27’56” W ‒ 57m alt., 16 June 2008, Drechsler-Santos & al. DS042SE (URM 80422); Poço Redondo, Trilha de Angicos, on living Caesalpinia sp. , 9º38’08” S, 37º40’42” W ‒ 30m alt., 14 June 2008, Drechsler-Santos DS001SE (URM 80419); ibid, on living Caesalpinia sp. , 9º39’08” S, 37º40’42” W ‒ 30m alt., 14 June 2008, Drechsler-Santos & al. DS009SE (URM 80568); Porto da Folha, on living Caesalpinia sp. , 9º54’40” S, 37º16’16” W ‒ 10m alt., 15 June 2008, Drechsler-Santos & al. DS026SE (URM 80577).

Figures

FIGURE 2. Phellinotus species. P. neoaridus. (A) holotype on specific host (lenticels of Caesalpinia sp. in detail); (B) applanate to triquetrous basidioma with a distinct ochre-orange margin (URM80410); (C) ungulate with strongly rimose upper surface and brownish margin (URM80641) (Bars = 5 cm); (D): isotype context and tubes lacking tissue layer between the tubes, in detail (D*) the black line near the upper surface (Bars = 1 cm); (E–G) basidiospores, white arrows are indicating the adaxially flattened surface [(E) lactophenol, (F) KOH+, (G) CB±; Bars = 5 μm]; P. piptadeniae. (H) paratype (IAC4365); (I) context in detail showing the distinct black line in the paratype; (J) mature triquetrous, developing applanate basidiomata on Piptadenia spp. (URM 80768) (Bars = 5 cm); (L) black line and tissue layer between the tubes are showing in detail in L and L* (Bars = 1 cm); (M–O) basidiospores, white arrows are indicating the adaxially flattened surface [(M): lactophenol, (N) KOH+, (O) CB±; Bars = 10 μm]. Photos of basidiomata (A, B, C, D, H, I, J) by Elisandro Ricardo Drechsler-Santos except for ‘L’ which is by Gerardo Lucio Robledo; photos of spores (E, F, G, M, N, O) by Carlos Salvador- Montoya.

FIGURE 3. Microscopic elements of Phellinotus species in line drawings. (A, C, E) P. piptadeniae (IAC 4365). (A) hyphal system of context; (C) skeletal hyphae from trama of tube layer; (E) basidiospores. (B, D, F) P. neoaridus (URM 80362). (B) hyphal system of context; (D) skeletal hyphae from trama of tube layer; (F) basidiospores. Drawings by Gerardo Lucio Robledo.