Vuilleminia tropica Hembrom, A. Ghosh, A. Parihar & K. Das 2022, sp. nov.
Creators: name: Buyck, Bart
name: Eyssartier, Guillaume
name: Armada, François
name: Corrales, Adriana
name: Hembrom, Manoj Emanuel
name: Rossi, Walter
name: Bellanger, Jean-Michel
name: Das, Kanad
name: Dima, Bálint
name: Ghosh, Aniket
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Agaricomycetes
Corticiales
Corticiaceae
Vuilleminia
Vuilleminia tropica

description: 120. Vuilleminia tropica Hembrom, A. Ghosh, A. Parihar & K. Das, sp. nov.
(Figs 23-25)
DIAGNOSIS. — Differs from other species because of its tropical distribution, lemon yellow hymenophore delimited by a white floccose margin when actively growing and its erumpent nature with a tendency to grow on bark of dead wood, further also by the smaller basidiospores (11-16 × 5-8 µm), basidia (45-75 × 7-9 µm) and rare dendrohyphidia in the hymenium, the thin- to distinctly thick-walled generative hyphae with clamped septae.
HOLOTYPE. — India. Jharkhand, Rajmahal hills, Sahibganj district, Brindaban Panchayat, Joshkuti, on dead fallen branch of Bauhinia vahilii Wight & Arn., 63 m, 25°01’50.9”N, 87°42’17.2”E, 29.VIII.2013, M. E. Hembrom, MEH-70133 (holo-, CAL [CAL1845]!).
MYCOBANK. — MB840192.
GENBANK. — MZ314343 (nrITS, holotype), MZ314344 (nrITS, paratype); MZ314347 (nrLSU, holotype), MZ314346 (nrLSU, paratype).
ETYMOLOGY. — Tropica (Lat.) refers to the tropical distribution of the taxon.
ADDITIONAL MATERIAL STUDIED. — India. Bihar, Valmiki National Park, West Champaran district, Valmiki Nagar, on the fallen branch (un-barked wood) of Shorea robusta Gaertn., 27°26’26.1”N, 83°56’10.4”E, 141 m, 2019, M. E. Hembrom, MEH-19; West Bengal, Howrah district, AJCBIBG, Div.: VIII near Kyd monument, on dead branch of Psidium guajava L., 5 m, 22°33’25.4”N, 88°17’30.1”E, 30.VII.2020, M. E. Hembrom, KMA-20-26; Bihar, West Champaran, Valmiki National Park, Ganouli Forest Range, on the decorticant log of unidentified tree, 180 m, 27°22’33.6”N, 83°59’38.5”E, 01.VIII.2020, A. V. Kisku, MEH-20-50 (CAL1846).
DESCRIPTION
Basidiomata
Annual, widely effused (5-200 × 5-100 mm or even much larger), up to 0.3 mm thick, growing on bark and more or less separable when fresh, but becoming closely adnate when dried, initially starting to form as small round patches with white margin that quickly merge to form large, effused, crusty basidiomata, leathery and slightly sticky when fresh, brittle and waxy on drying. Margin up to 1 mm wide when actively growing, distinct to indeterminate in older specimens, sterile, floccose, chalky-white (1-2A1) to pale yellow (3A3).
Hymenophore
Smooth, glabrous, pale yellow to pastel yellow (3A3-4) when young then yellow to lemon yellow (3B5-8), becoming bright yellow to almost egg yellow at maturity, finally ochraceous in older dried specimens.
Flesh
Papery thin, waxy, yellowish white (1-2A2).
Hyphal system
Monomitic, generative hyphae septate, clamped at most septa, thin- to moderately thick-walled, branched, with smooth, hyaline, acyanophilic walls (but contents cyanophilic) and not amyloid.
Subhymenium & subiculum
Composed of compactly arranged vertical elements ending with indistinct subiculum with crystal elements; basal hyphae 3-5 µm wide, thin to moderately thick-walled, loosely interwoven, cytoplasmic contents cyanophilic; hyphae in the middle part 2-4 µm wide, towards subhymenium less interwoven and less branched, more or less parallel, thin-walled.
Hymenium
Composed of hyphoid elements, rare delicate dendrohyphidia, basidia and basidioles; hyphoid elements 30-45 × 3-4 µm, embedded to projecting up to 16 µm beyond the hymenium, cylindrical, smooth. Dendrohyphidia often difficult to observe, up to 2 µm wide, less branched, thin-walled, smooth, hyaline. Basidia 45-75 × 7-9 µm, clavate to elongated cylindrical, 4-sterigmate with sterigmata 3-10 × 1-3 µm, clamped at base with clamps often delicate and difficult to observe, thin-walled, when young filled with dense and globular contents, becoming empty and collapsed with maturity, smooth, hyaline, when older with occasionally transverse septa.
Basidiospores
11-13.6-16 × 5-6.35-8 µm, Q = 1.7-2.15-2.76, cylindrical to narrowly ellipsoid, moderately thick-walled with walls up to 1 µm thick, smooth, hyaline and acyanophilic; contents cyanophilic, inamyloid.
NOTES
Vuilleminia Maire is mostly confined to Europe with few exceptions (Bernicchia & Gorjón 2010; Ghobad-Nejhad et al. 2010). Very recently, one of us (MEH) came across some specimens in eastern tropical India growing on bark as well as invading the xylem vessels below the bark. Morphological features and molecular phylogeny place these specimens in the genus Vuilleminia, but none of the described species matches the present collections.
The genus Vuilleminia fits the morphological features of our species, including the gelatinous (when fresh) to ceraceous basidiomata with monomitic hyphal system and clamped hyphae, pedicellate-clavate basidia producing large basidiospores and presence of dendrohyphidia (Hjortstam et al. 1988; Bernicchia & Gorjón 2010; Ghobad-Nejhad et al. 2010; Ghobad-Nejhad & Duhem 2013).
Growing in the tropics and forming basidiomata (up to 300 µm thick) with lemon yellow hymenial surface and whitish floccose margin on fallen wooden logs, make it easy to identify our species in the field. The more or less thickwalled basidiospores with cyanophilic cytoplasmic contents are unrecorded from other Vuilleminia, viz. V. alni Boidin, Lanq. & Gilles; V. comedens (Nees) Maire; V. corticola Parmasto, V. coryli Boidin, Lanq. & Gilles; V. cystidiata Parmasto; V. erastii Ghob. -Nejh., V. macrospora (Bres.) Hjortstam; V. megalospora Bres.; V. nilsii Ghob. -Nejh. & Duhem, V. oyensis Duhem & M. Gérard, and V. pseudocystidiata Boidin, Lanq. & Gilles. (Hjortstam et al. 1988; Gorjón 2009; Bernicchia & Gorjón 2010; Ghobad-Nejhad et al. 2010, 2012; Ghobad-Nejhad & Duhem 2013). Many Vuilleminia have numerous dendrohyphidia, but in the present species dendrohyphidia are very few and become difficult to trace in older specimens and usually lack any side branching.
Our phylogeny places this novel species sister to V. macrospora, which differs morphologically in its white basidiomata with abundant dendrohyphidia, and capitate, thick-walled, tubular cystidia, and it also has a temperate distribution (Bernicchia & Gorjón 2010; Ghobad-Nejhad et al. 2010). Vuilleminia nilsii shares the creamish to yellowish white hymenial surface and basidiospores with cyanophilic contents (Ghobad-Nejhad & Duhem 2013), but its spores are thinwalled and longer (14.5-18 µm).
description: Published as part of Buyck, Bart, Eyssartier, Guillaume, Armada, François, Corrales, Adriana, Hembrom, Manoj Emanuel, Rossi, Walter, Bellanger, Jean-Michel, Das, Kanad, Dima, Bálint & Ghosh, Aniket, 2022, Fungal biodiversity profiles 111 - 120, pp. 23-61 in Cryptogamie, Mycologie 20 (2) on pages 54-59, DOI: 10.5252/cryptogamie-mycologie2022v43a2, http://zenodo.org/record/7828891