Gyroporus madagascariensis Buyck, O. Asher & Davoodian, 2020

Davoodian, Naveed, Hosaka, Kentaro, Raspé, Olivier, Asher, Olivia A., Franck, Alan R., Kesel, André De, Delaney, Terrence P., Ammirati, Joseph F., Nagasawa, Eiji, Buyck, Bart & Halling, Roy E., 2020, Diversity of Gyroporus (Gyroporaceae, Boletales): rpb 2 phylogeny and three new species, Phytotaxa 434 (3), pp. 208-218 : 212

Gyroporus madagascariensis Buyck, O. Asher & Davoodian , sp. nov. ( Fig. 2 )

Type:— MADAGASCAR. Central Plateau: ca. 25 km south of Antsirabe, on Mount Ibity, ca. 2000 m elev., 27 Jan 2008, B. Buyck 08.211 (holotype PC! [PC0142530]).

Etymology: The specific epithet refers to Madagascar, the country where the type locality of this species is located.

MycoBank: MB831758

Pileus 3–4 cm broad, convex to plano-convex, dry, glabrous to finely and densely fibrillose (elements upright), rimose in some areas (revealing white context), semi-mottled light to dark brown with red and yellow tones 7E-F6,5 ( Kornerup & Wanscher 1978). Flesh white, unchanging. Tubes adnexed, whitish-yellow at maturity, whitish when immature, some areas discoloring to orange. Stipe 4–6 cm long, 0.9–1.5 cm broad, curved, surface slightly lumpy/uneven, dry, subconcolorous with pileus, texture similar to pileus though elements more loosely arranged.

Spores 6.7–8.4(–9.1) × 4.1–5.2 μm (Q m =1.7), ellipsoid, hyaline, sometimes appearing with contents. Basidia 19.3–28.8 × 6.2–12 μm, clavate, with clearly visible sterigmata. Basidioles 12–36 × 4.1–10.1 μm, generally short, round and inflated (when mature), or long with rounded tips and slightly inflated (when young). Cheilocystidia and pleurocystidia none found, apparently absent or rare. Pileipellis a moderately tangled, more-or-less upright trichoderm, the hyphae appearing pale hyaline brown when clumped (hyaline individually), 6–20µm broad, the end cells tapered to rounded points (rarely mucronate/mucronate-cystidioid), 10–14µm broad at widest point. Clamp connections present in pileipellis.

Ecology and distribution: Known from solitary collections from primary tapia ( Uapaca bojeri ) woodland. Thus far known only from Madagascar.

Additional material examined: MADAGASCAR. Central Plateau: ca. 25 km south of Antsirabe, on Mount Ibity, ca. 2000 m elev., 27 Jan 2008, B. Buyck 08.202 (PC0142529).

Commentary: G. madagascariensis has a moderately mottled pileus; G. mcnabbii , also known from the southern hemisphere ( Australia and New Zealand), displays a mottled pileus as well. In addition, occasional orange discoloration of the hymenophore (especially pores) occurs in both G. madagascariensis and G. mcnabbii . G. madagascariensis and G. mcnabbii are geographically and ecologically distinct, associating with different ectomycorrhizal hosts in their respective areas ( G. mcnabbii associates primarily with Myrtaceae ). Additional specimens of both species are needed to fully discern the range of variation and assess the consistent morphological distinctions between the two. G. madagascariensis is phylogenetically closer to G. castaneus s.l. and related “castaneoid” clades (e.g. G. mcnabbii and close relatives, G. naranjus [ Australia] and sister Central and West African lineages, etc.) than to G. cyanescens , G. longicystidiatus and related clades.

Figures

FIGURE 2. Gyroporus madagascariensis sp. nov. basidiocarps. Counterclockwise from bottom-left: Buyck 08.211 (holotype); Buyck 08.211 (holotype), hymenophore view; Buyck 08.202, hymenophore view; Buyck 08.202. Images: Bart Buyck.