Sclerotus Xavier de Lima, 2022

X, Vitor, Lima, avier de, T, Virton Rodrigo, Oliveira, argino de, C, Nelson, Lima-Júnior, orreia de, C., José Ribamar, Oliveira-Filho, Santos, Carla, Lima, Nelson & Gibertoni, Tatiana Baptista, 2022, Taxonomy and phylogenetic analysis reveal one new genus and three new species in Inonotus s. l. (Hymenochaetaceae) from Brazil, Cryptogamie, Mycologie 20 (1), pp. 1-21 : 10

Sclerotus Xavier de Lima , gen. nov.

TYPE SPECIES. — Sclerotus extensus (Lév.) Xavier de Lima

MYCOBANK NUMBER. — MB833801.

ETYMOLOGY. — Scler-,(Greek) hard; otus (Greek) ear.

SUBSTRATE. — Dead angiosperm.

DESCRIPTION

Basidioma perennial, pileate, resupinate to effused-reflexed, hard; pilear surface, when present, initially finely tomentose, but tomentum soon wearing away exposing the black line in the context like a hard crust or cuticle, narrowly sulcated, covering all pileus surface. In section, basidioma applanate, context dark brown; crust glossy, thick. Hyphal system dimitic in context and tube trama. Generative hyphae simple septate. Hyphae darkening in 3% KOH. Hymenial setae present, strongly ventricose, dark, with a narrow lumen. Basidiospores ellipsoid to subglobose, pale yellow, slightly thick-walled, IKI-, CB-. On dead angiosperm.

REMARKS

This genus differs from other poroid Hymenochaetaceae by the combination of the presence of strongly ventricose and dark hymenial setae and a thick black line that is exposed after the tomentum wears away ( Fig. 5 ). The dimitic nature of tube trama and context, the pigmented thick-walled basidiospores and presence of hymenial setae makes this genus morphologically similar to Phellinus s.s., but it can be differentiated by the unique hymenial setae. This genus, so far, is represented by a single tropical species, S. extensus .

Figures

FIG. 5. — Sclerotus extensus (Lév.) Xavier de Lima: A, dried basidiomata of URM87072; B, dried basidiomata of URM89390; C, longitudinal section of the dried basidioma of URM89538, red arrows pointing the black line in the context; D, skeletal of the context in 3% KOH; E, hymenial setae (URM89538) in 3% KOH; F, basidiospores (URM89538) in 3% KOH. Scale bars: A-C, 1 cm; D-F, 10 μm.