Phellinotus neoaridus Drechsler-Santos & Robledo 2016, in Drechsler-Santos et al., Phytotaxa, 261(3), 218-239 (2016).
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.
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.
Index Fungorum Number: IF805901
Figure 1. 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].
Figure 2. P. neoaridus (URM 80362). (B) hyphal system of context; (D) skeletal hyphae from trama of tube layer; (F) basidiospores. Drawings by Gerardo Lucio Robledo.
Drechsler-Santos, E. R., Robledo, G. L., Lima-Junior, N. C., Malosso, E., Reck, M. A., Gibertoni, T. B., ... & Rajchenberg, M. (2016). Phellinotus, a new neotropical genus in the Hymenochaetaceae (Basidiomycota, Hymenochaetales). Phytotaxa, 261(3), 218-239.
Särkinen, T., Iganci, J. R. V., Linares-Palomino, R., Simon, M. F. & Prado, D. E. (2011). Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study. BMC Ecology 11: 27.