Volvariella reidii Heinem.

Caballero, Fernando, Justo, Alfredo, Parra, Luis A., Angelini, Claudio, Consiglio, Giovanni, Dovana, Francesco, Ferisin, Giuliano, Kaygusuz, Oğuzhan, Knudsen, Henning, Llimona, Xavier, Muñoz, Guillermo, Daniëls, Pablo P., Pérez-De-Gregorio, Miquel À., Ševčíková, Hana, Valverde, Andrés & Vizzini, Alfredo, 2025, Taxonomic and phylogenetic overview of the genus Volvariella (Volvariellaceae), with a focus on European species, Phytotaxa 680 (1), pp. 1-85 : 39

9. Volvariella reidii Heinem. , Bulletin du Jardin Botanique National de Belgique 48(1-2): 239. 1978. ( Fig. 17 ).

≡ Volvariella parvispora D.A. Reid, Transactions of the British Mycological Society 68(3): 327. 1977 (nom. illeg., Art. 53.1, non V. parvispora Heinem. , Bulletin du Jardin Botanique National de Belgique 45(1–2): 192. 1975)

Typification status:— Holotype: UNITED KINGDOM. England, near Southampton, Old Winchester Hill, growing in litter under Crataegus , together with Clitocybe nebularis , 12 October 1974, P.J. Houlton, KM 94146! (KM).

Description:— Pileus 10–50 mm diam., ovoid when young, expanding to conico-convex or conico-campanulate, plano-convex in older specimens, usually with a distinct central umbo; surface smooth; white, sometimes with brown tinges at centre, not hygrophanous; margin slightly striate, irregular and exceeding the lamellae. Lamellae crowded, free, broadly ventricose, white when young, becoming salmon pink or pinkish brown with age; edge irregular, white and floccose, or concolorous and more or less even. Stipe 30–60 × 4–6 mm, cylindrical, slightly widening towards the base, straight or curved; surface white, with brown tinges, finely pubescent. Volva membranaceous, saccate, white, sometimes with brown tinges, with 2–3 lobes; rhizomorphs not observed. Context white, thin. Smell indistinct.

Basidiospores (n=51, c=1) 4.0–5.4 × 3.2–4.3 μm, avl × avw = 4.8 × 3.7 μm, Q = 1.15–1.43, avQ = 1.29, broadly ellipsoid to ellipsoid, thick-walled, with barely distinct hilar appendage. Basidia 22–31 × 8–10 μm, tetrasterigmate, clavate or subclavate. Lamella edge heterogeneous. Cheilocystidia common, 55–112 × 12–29 μm, lageniform with elongated neck, fusiform, clavate, many with an oleaginous, globose covering at apex. Pleurocystidia scarce, 47–68 × 10–25 μm, mostly lageniform with an elongated neck. Pileipellis a cutis or an intermediate cutis-trichoderm, with terminal elements, 5–30 μm wide, often constricted at the septa, hyaline. Stipitipellis a cutis, or a cutis-trichoderm in the upper part of the stipe, with cylindrical hyphae, 10–19 μm wide. Volva composed of interwoven, cylindrical, septate hyphae, 6–26 μm wide, with common septa; individual hyphal segments often constricted at the septa. Clamp connections absent in all parts examined.

Habit, habitat, and phenology:—Solitary or gregarious. Terrestrial, collected among Picea needles, and also in litter under Crataegus , together with Clitocybe nebularis (Batsch.) P. Kummer (1871: 124) . October.

Distribution:—Recorded from the UK, Finland, Denmark, and Spain.

Additional collections examined:— SPAIN. Navarra: Basaburua , among the leaf litter (needles) of Picea abies , elev. 800 m, 3 October 2015, J. L. Albizu, ARAN-Fungi 01678 .

Nomenclatural comments:—This species was originally published under the name V. parvispora D.A. Reid ( Reid et al. 1977) , which is illegitimate because the name V. parvispora Heinemann (1975: 192) had been previously assigned to an African species found in Zaire (now the Democratic Republic of the Congo). Heinemann himself corrected this error ( Heinemann 1978), assigning the new epithet “ reidii ” in honour of Reid, the original author of this species.

Observations:— Volvariella reidii is characterized by its small spores, one of the smallest in the genus. In the collection of the original description, the spores measured 3.75–4.2 × 2.2–3.2 µm, while in our studied material the spores measured 4.0–5.4 × 3.2–4.3 μm. Macroscopically, the surface of the pileus is originally described as smooth, opaque and non-fibrillose, a character that also occurs in the collection studied and differs from a large number of other species in the genus that tend to have a fibrillose pileus surface, generally with small scales. At the moment we accept these characters as valid for recognizing this species on a morphological basis.

Figures

FIGURE 17. Volvariella reidii. A. Basidiomes (ARAN-Fungi 01678). B–G. Microscopic characters (ARAN-Fungi 01678). B–C. Cheilocystidia; D. Pleurocystidia; E. Spores; F. Pileipellis; G. Volva hyphae. Bar: (B–G) = 10 µm. Photos by J.L. Albizu (A), F. Caballero (B–G).