Gyroporus lacteus Quél., Enchir.

Vizzini, Alfredo, Angelini, Claudio & Ercole, Enrico, 2015, Molecular confirmation of Gyroporus lacteus and typification of Boletus cyanescens, Phytotaxa 226 (1), pp. 27-38 : 31-35

Gyroporus lacteus Quél., Enchir. fung. (Paris): 161 (1886) Figs. 4–6

Basionym: Boletus lacteus Lév., Annls Sci. Nat., Bot. , sér. 3, 9: 124 (1848), nom. illegit. (Art. 53), non Boletus lacteus Batsch, Elench.

fung. ( Halle): 103 (1783) ≡ Gyroporus cyanescens var. lacteus (Quél.) Quél., Fl. mycol. France (Paris): 425 (1888) Lectotype (iconotype) (designated here): Léveillé 1848, Fragments mycologiques. Annales des Sciences Naturelles Botanique , Tab. 9

(1–2) (MBT202280) ( Fig. 4a ). Epitype (designated here): MCVE 28582 (MBT202281), Italy, Veneto, Bosco Nordio, Chioggia (VE), sandy soil, with Pinus pinea and

Quercus ilex , 04 October 2014, C. Angelini.

Pileus fleshy, 9–15(–17) cm diam., at first hemispheric, then convex, finally fully expanded, applanate and pulvinate; surface matt and dry, cuticle slightly exceeding the pileus margin, at first unbroken and velutinous, but when expanding breaking up into more or less large and irregular scales, consisting of bunches of coalescing hairs letting the whitish context shine through, entirely and strongly covered with sand which is difficult to wipe off, dull, whitish as long as the specimens remain buried, ochraceous-cream when they come out from the substrate, or typically orange-brown, like “bread crust”, in prematurely emerged specimens; immediately and strongly staining deep indigo blue or ink blue if handled or bruised. Pores irregular, straight-flattened as long as the pileus is unexpanded or semi-expanded, then with a swollen appearance like “beer foam”, small, snow white and more or less round when young, cream, greenish-cream, larger and sometimes slightly angular with age, bluish-grey when touched. Tubes free, thin, rather short when young, medium long in expanded specimens, concolorous with the pores, staining faded-watery blue when exposed. Stipe up to 14 × 7 cm, thick-set and proportional to the pileus, sometimes longer than the pileus diameter, other times shorter or equal, almost always buried for most of its length, mostly cylindrical, rarely slightly enlarged downwards, usually with a rounded base, only occasionally shortly pointed, rarely subrooting and then curved at the lowermost part of the base; surface almost smooth or slightly fibrillose-floccose, without horizontal cracks, snow white in the part under the ground, but cream, orange-brownish, like the pileus surface but less deep in tones in the part above the ground, entirely covered with sand which is difficult to wipe off, typically confined to the part not touching the hymenophore when at the primordial stage, instantly and strongly staining ink blue where touched; corticated in section, with a spongy context tending to crack horizontally, then cavernous, with large rhomboid cavities in fully-grown specimens, whitish, when cut immediately indigo blue, but the colour change is less strong than that of the outer surfaces of the pileus and above all of the stipe; almost odourless when young, then the smell becomes more definite, aromatic, in any case unpleasant, in fully-grown specimens, especially at stipe base. Spore print yellowish.

Basidiospores [40/4/2] (8.0–) 8.2–10.5 (–11.0) × (4.2–) 5.0–6.0 (–6.2) μm, on average 9.47 × 5.54 μm, Q = (1.45)

1.47 × 2.1 (2.3), Qm = 1.67, smooth, elliptic in face view, subelliptic or slightly reniform-phaseoliform (dorsal line nearly straight) in profile, rarely subcylindrical, light yellow-greenish in water. Basidia clavate, usually 4-spored, rarely 2-spored, 30–40 × 10–15 μm, with sterigmata up to 7 μm long. Cheilocystidia abundant, up to 50 × 10 μm, very variable, fusiform, lageniform, cylindrical to clavate, rarely septate and sometimes minutely encrusted at apex. Pleurocystidia similar to cheilocystidia but infrequent. Caulocystidia not seen. Pileipellis as a cutis consisting of thinwalled radially arranged hyphae, with some repent terminal elements, up to 15 μm wide. Pigment yellowish-ochre, both intracellular and parietal, sometimes also minutely encrusting. Stipitipellis with hyphae similar to those of the pileipellis. Clamp connections present in all tissues.

Habit, habitat and distribution:—autumnal (early October to mid November), growing gregariously and deeply buried (long semihypogean) in sandy soil, at the edge, or more frequently in paths or in clearings, of Mediterranean woods with pines and holm oaks ( Pinus pinea and Quercus ilex ) close to the sea. So far known from France, Italy and Spain.

Collections examined:— ITALY, Veneto: Bosco Nordio, Chioggia (VE), sandy soil, with Pinus pinea and Quercus ilex , 02 November 2013, C. Angelini, MCVE 28581 (MCVE!); ibidem 04 October 2014, C. Angelini, MCVE 28582 (epitype, MCVE!).

Figures

FIGURE 4. Gyroporus lacteus. Basidiomata. a. Léveillé’ s plate 9 (1–2) (lectotype, iconotype). b–e. Collection MCVE 28582 (epitype, photos by C. Angelini). Scale bars: 5 cm.

FIGURE 5. Gyroporus lacteus. a. Basidiomata. b. Basidiospores (in ammoniacal Congo red). c. Cheilocystidia (in ammoniacal Congo red).All from MCVE 28582 (epitype, photos by C. Angelini). Scale bars: a = 5 cm; b = 10 μm; c = 20 μm.

FIGURE 6. Gyroporus lacteus. a. Habitat. b–c. Habitat and habit. Photos by C. Angelini.