Inonotus pseudolinteus Vlasák & Y.C. Dai, 2013

Vlasák, Josef, Li, Hai-Jiao, Zhou, Li-Wei & Dai, Yu-Cheng, 2013, A further study on Inonotus linteus complex (Hymenochaetales, Basidiomycota) in tropical America, Phytotaxa 124 (1), pp. 25-36 : 30-31

Inonotus pseudolinteus Vlasák & Y.C. Dai , sp. nov. ( Figs. 4 , 5 )

MycoBank MB 803767

Type. — VENEZUELA. SanFelix , town park, on living angiosperm wood, 2 April 2004, J. Kout, JV 0404 / 35-K (Holotype in PRM 861184 , isotype in BJFC 14700 ) .

Etymology.— pseudolinteus (Lat.) : resembling Inonotus linteus .

Fruitbody. —Basidiomata perennial, pileate, semicircular to dimidiate, ungulate, woody hard when dry. Pilei projecting up to 3 cm, 4.5 cm wide and 4.5 cm thick at base. Pileal surface fuscous to black, concentrically sulcate, matted, cracked with age; margin obtuse, fuscous. Pore surface cinnamon to greyish brown when dry; sterile margin indistinct; pores circular, 4–5 per mm; dissepiments thin to moderately thick, about 40–100 Μm thick, entire. Context cinnamon, woody hard, up to 4 cm thick. Tubes cinnamon to yellowish-brown, woody hard, up to 5 mm long, tube layers mostly indistinct.

Hyphal structure. —Hyphal system monomitic in context, dimitic in the hymenophoral trama; generative hyphae simple septate; tissue darkening in KOH.

Context. —Generative hyphae yellow to golden brown, varying from slightly thick-walled to thick-walled, frequently simple septate, straight, more or less regularly arranged, 2.5–4 Μm in diam.

Tubes. —Generative hyphae hyaline to pale yellowish, thin- to slightly thick-walled, moderately branched, frequently septate, 1.8–2.5 Μm in diam; skeletal hyphae dominant, yellowish brown, thick-walled with a distinct lumen, unbranched, straight, subparallel along the tubes, 2–3 Μm in diam. Hymenial setae rare in the hymenium and dissepiments, mostly subulate, sometimes ventricose, dark brown, thick-walled, 20–34 × 5–7 Μm; basidia clavate, with four sterigmata and a simple septum at the base,13–15 × 6–7 Μm; basidioles in shape similar to basidia, but slightly smaller.

Basidiospores. — Broadly ellipsoid, usually collapsed when mature, yellowish and thick-walled, smooth, IKI–, CB –, (4.7–)4.8–5.8(–6) × (3.3–)3.7–4.6(–4.9) Μm, L= 5.23 Μm, W = 4.09 Μm, Q = 1.25–1.27 (n = 60/2).

Paratypes. — USA. Florida, Florida Keys, Windley Key, Fossils Reef Geological State Park , angiosperm wood, 22 December 2003, J. Vlasák Jr., JV 0312 / 22.10-J ( PRM 861185 , JV, BJFC 14701 ), JV 0312 /20.10-J ( JV).

Notes.— Inonotus pseudolinteus is morphologically very similar to I. linteus . However, I. linteus has abundant hymenial setae, while hymenial setae are rarely present in I. pseudolinteus . In addition, skeletal hyphae in Inonotus linteus become swollen in KOH, while they keep unchanged in I. pseudolinteus .

Inonotus pseudolinteus is probably widely distributed in Central America. This species was treated as Inonotus sp. by Tian et al. (2013), and its ITS sequences ( AF 534075 and AY 558629 ) was recognized as I. linteus in GenBank.

Figures

FIGURE 4. Basidiocarp of Inonotus pseudolinteus sp. nov. (Holotype).

FIGURE 5. Microscopic structures of Inonotus pseudolinteus sp. nov. (drawn from the holotype). a: Basidiospores; b: Basidia and basidioles; c: Setae; d: Hyphae from trama; e: Hyphae from context.