Volvopluteus canalipes (Murrill) Montoya, Bandala & Esqueda, 2021

Montoya, Leticia, Bandala, Victor M. & Esqueda, Martin, 2021, Volvopluteus canalipes comb. nov. (Pluteaceae) from the Sonoran Desert of Mexico, Phytotaxa 505 (3), pp. 275-285 : 278-281

Volvopluteus canalipes (Murrill) Montoya, Bandala & Esqueda , comb. nov. Figs. 2–6

Basionym: Volvariopsis canalipes Murrill, Mycologia 30: 368, 1938.

≡ Volvariella canalipes (Murrill) Shaffer, Mycologia 49: 549, 1957.

MycoBank: 839091

Description:— Pileus 30–60 mm diam., broadly conical becoming more or less convex, smooth, glabrous, covered by sand particles and thick patches of volva remnants, shiny, whitish to pale yellow (2A2–A3); margin entire, not striate, eroded in some specimens. Pileus context white and odor pleasant. Lamellae moderately close (± 1mm spaced), free, with up to 3 lamellulae of different lengths, slightly ventricose, pale yellow (4A3–3B4), then pink to brownish pink, with concolorous even edge. Stipe 32–77 × 5–6 mm, white to pale grey (1A2–1B2), cylindrical but slightly tapering towards the apex, broader at the base (7–9 mm wide), strongly furrowed, with blunt ridges, solid, half of its length buried in the sand. Volva 18–34 × 10–31 mm, cup-like, thick, in section a marginate-bulbous stipe base with limbate volva with free irregular margin, shallow, yellowish white to dull yellow (3A2–3B3).

Basidiospores 14.5–18 (–20) × 8–10 (–11) µm; L= 16 µm, W= 9.3 µm, Q = 1.75, n= 45, ellipsoid or somewhat narrowly ellipsoid to oblong, hyaline to yellowish, guttulate, smooth, wall up to 1 µm thick, inamyloid. Basidia 40–63 (–72) × 14–17 µm, clavate, 4-spored, hyaline, inamyloid, with refractive contents, thin-walled, clampless. Pleurocystidia 50–73 × 13–24 µm, ventricose-rostrate, ventricose-mucronate, some broadly fusiform-mucronate, thinwalled, hyaline, inamyloid, infrequent, scattered on the hymenial layer, clampless. Cheilocystidia 30–52 × 16–28 µm, broadly clavate or subglobose-clavate, ventricose-mucronate forms can be present, thin-walled, hyaline, inamyloid, clampless. Pileipellis a continuous cutis layer, sometimes with irregular bulges, with pale yellowish to hyaline, slightly gelatinized hyphae, 4–10 µm diam, thin-walled, smooth, frequently with refringent septa, in water or in KOH the gelatinous matrix disappears after 2–4 minutes, leaving only traces of gelatinization, in some areas the hyphae are arranged in mounds. Pileus trama composed of loosely packed inflated hyphae 10–35(–48) intermixed with smaller diameter hyphae, 5–8 µm diam, septate, thin-walled, hyaline, with slightly refractive contents. Hymenophoral trama convergent, with inflated hyphae 12–20 µm diam, with some intermixed smaller diameter hyphae, 5–7 µm diam., cylindrical, thin-walled, septate, some septa slightly refringent. Clamp connections absent.

Habitat: — Gregarious, semi-hypogeous in sandy soil, in sandy desert vegetation, with dominant vegetation of Larrea tridentata , Ambrosia dumosa , A. deltoidea and Prosopis glandulosa .

Specimens examined: — MEXICO. Sonora, Municipality of Sonoyta, Altar Desert sub-province, Ejido Punta Peñasco , 31°43’19.97” N, 113°13’27.92” W, elev., 154 m, 25 February 2012, M . Esqueda & A . Gutiérrez ( UES 10301) .

Micromorphological features observed in the holotype of Volvariopsis canalipes ( Figs. 4–5a,c )

Basidiospores 14–18 (–21) × 8–11 (–12) µm; L= 16.13, W= 9.58 µm; Q= 1.7 µm, n= 45, ellipsoid. Basidia 36–62 × 15–22 µm, tetrasporic, hyaline, thin-walled, clampless. Pleurocystidia 52–85 × 15–26 µm, ventricose-mucronate, broadly fusiform-mucronate, clampless. Lamellae edge not completely recovered due to collapse of the tissue, but some Cheilocystidia observed, 52–64 × 21–26 µm, broadly clavate or slightly subglobose-clavate, some broadly clavate with a small apical papilla. Pileipellis a cutis slightly gelatinized in some parts, hyphae, 4–8 µm diam.

Specimen examined: — USA. Florida, Green Cove Springs , sandy railroad bank, 3 March 1926, W. A . Murrill 8382 (Holotype FLAS F9975 ) .

Figures

FIGURE 2. Basidiomes of Volvopluteus canalipes, UES 10301, scale bars = 10 mm. Photos by: A. Gutierrez.

FIGURE 3. Volvopluteus canalipes UES 10301: a basidiospores, b basidia, c pleurocystidia, d cheilocystidia. Scale bars = 10 µm. Drawings by: D. Ramos.

FIGURE 4. Volvopluteus canalipes holotype F9975: a basidiospores, b basidia, c pleurocystidia, d cheilocystidia. Scale bars = 10 µm. Drawings by: D. Ramos.

FIGURE 5. Volvopluteus canalipes pileipellis showing only slight gelatinization. a, c holotype F9975, b, d UES 10301. Scale bars = 25 µm. Photos by: D. Ramos.

FIGURE 6. Basidiome of Volvopluteus canalipes. Holotype of Volvariopsis canalipes, Murrill 8382 (FLAS F9975). Scale bar = 10 mm.