Sidera americana Z.B. Liu & Yuan Yuan, 2023

Liu, Zhan-Bo, Zhou, Hong-Min, Liu, Hong-Gao & Yuan, Yuan, 2023, Taxonomy and phylogeny of Sidera (Hymenochaetales, Rickenella clade) from China and North America revealing two new species, MycoKeys 96, pp. 173-191 : 173

Sidera americana Z.B. Liu & Yuan Yuan sp. nov.

Figs 2 , 3

Diagnosis.

Sidera americana is characterized by annual, resupinate basidiomata with silk sheen when dry, round pores (9-11 per mm), a dimitic hyphal system, and allantoid basidiospores measuring 3.5-4.2 × 1 μm.

Holotype.

USA. Connecticut, New Haven, West Rock Park, on rotten stump of Pinus , 15.VII.2012, Dai 12730 (BJFC 013037, isotype in CFMR).

Etymology.

Americana (Lat.): referring to the species occurring in North America.

Basidiomata.

Annual, resupinate, soft and without odor or taste when fresh, soft corky when dry, up to 14 cm long, 6 cm wide, and approximately 2 mm thick at center; pore surface white when fresh, becoming cream to buff with silk sheen when dry; sterile margin indistinct; pores round, 9-11 per mm; dissepiments thin, lacerate; subiculum very thin to almost absent; tubes concolorous with poroid surface, up to 2 mm long.

Hyphal structure.

Hyphal system dimitic; generative hyphae with clamp connections; skeletal hyphae dominant; all hyphae IKI-, CB-; tissue unchanged in KOH.

Subiculum.

Generative hyphae hyaline, thin-walled, unbranched, 1-2.5 μm in diam; skeletal hyphae dominant, thick-walled with a wide lumen, frequently branched, flexuous, interwoven, 2-3 μm diam.

Tubes.

Generative hyphae hyaline, thin-walled, unbranched, 1-2 μm in diam, dominating at dissepiment edges; skeletal hyphae dominant in tube trama except dissepiment edges, thick-walled with a wide lumen, unbranched, flexuous, interwoven, 2-3 μm diam; rosette-like crystals abundant, 3-12.5 μm in diam; cystidia absent; cystidioles present, fusoid, hyaline, thin-walled, basally swollen, with a sharp or often hyphoid neck, 13.4-15 × 3.2-4 μm; basidia barrel-shaped, hyaline, bearing four sterigmata and with a basal clamp connection, 6-7 × 3-4.2 μm; basidioles in shape similar to basidia, but slightly shorter.

Spores.

Basidiospores allantoid, hyaline, thin-walled, smooth, occasionally with one or two guttules, IKI-, CB-, (3.2-)3.5-4.2(-5) × 1(-1.3) μm, L = 4 μm, W = 1.04 μm, Q = 3.74-3.96 (n = 60/2).

Additional specimen examined.

Canada, Ontario, Hamilton, McMaster University, Botanical Garden, on rotten angiosperm wood, 18-20.VII.2017, Dai 19173 (BJFC 027641).

Figures

Figure 2. Basidiomata of Sidera americana (Holotype, Dai 12730). Photo by: Zhan-Bo Liu.

Figure 3. Microscopic structures of Sidera americana (Holotype, Dai 12730) a basidiospores b basidia and basidioles c cystidioles d hyphae from subiculum e hyphae from trama f hyphae at dissepiment edge. Drawings by: Hong-Min Zhou.