Amanita stubbosa J.E.I. Codjia, N.S. Yorou & Zhu L. Yang

Cao, Xiaolei, Yao, Zhaoqun, Zhao, Sifeng, Zhang, Lu, Chen, Mei Xiu & Tian, Fang, 2023, Amanita stubbosa, a new non amatoxin nor phallotoxin-containing species within Amanita sect. Phalloideae (Amanitaceae, Agaricales), from West Africa, Phytotaxa 592 (3), pp. 267-278 : 273-275

Amanita stubbosa J.E.I. Codjia, N.S. Yorou & Zhu L. Yang

Figs. 3 , 4 .

Mycobank No:—MB 847406

Etymology: —The epithet refers to the stubby shape of the stipe base.

Type:— BENIN. COLLINES PROVINCE, 08°36’21”N, 02°35’57”E, elev. 319 m, Forest Reserve of Toui-Kilibo, road between Kilibo and Toui, close to Ekpa village , 05 July 2021, Nourou S. Yorou, Holotype:—SYN5016 (UNIPAR), GenBank Acc. No.: (nrLSU= OQ608812, RPB2 = OQ605967, TEF1 -α = OQ605968 ).

Description:— Basidiomata small to medium-sized. Pileus 40‒70 mm in diam., at first hemispherical and then becoming convex and broadly convex at maturity, white (1A1), covered by whitish (1A1) small broadly adherent squamules or erected, pyramidal, subconical patchy volval remnants that are greyish (1C2) to whitish (1A1); margin non-striate when young then slightly striate at maturity, non-appendiculate, white (1A1), unchanging. Lamellae free, crowded, white (1A1) to pale yellowish white (2A2), lamellulae truncate. Stipe 40‒80 mm long × 5‒15 mm diam., almost cylindrical, stuffed, bulbous, white (1A1), covered by white (1A1) squamules; basal bulb marginate, stubby and tapering downward, dirty white (2B3) to white (1A1), upper edge with shortly limbate, white (1A1) volval remnants. Annulus apical, slightly sinuate, persistent, broad, membranous, skirt-like, with thickened edge, white (1A1) to pale yellowish white (2A2). Context white (1A1). Odor and taste not recorded. Spore print not recorded.

Lamellar trama bilateral. Mediostratum 35‒55 µm wide, composed of abundant ellipsoid to clavate inflated cells (35‒150 × 15‒35 µm) and abundant filamentous hyphae, 3‒5 µm wide; vascular hyphae scarce. Lateral stratum composed of ellipsoid to clavate inflated cells (45‒95 × 15‒35 µm), diverging at an angle of ca. 30° to 45° to the mediostratum; filamentous hyphae abundant, 3‒5 µm wide. Subhymenium 30‒50 µm thick, with 2‒3 layers of ovoid to subglobose or irregular cells, 12‒20 × 9‒15 µm. Basidia [40/1/1] (35‒) 36‒50 (‒53) × (9‒) 10‒12 (‒13) µm, clavate, 4-spored, basal septa lacking clamps. Basidiospores [70/1/1] (9‒) 10‒11 (‒11.5) × (7‒) 8‒9 µm, Q = (1.1) 1.2‒1.3 (1.4), Qm = 1.2 ± 0.05, broadly ellipsoid to ellipsoid, smooth, colorless, weakly amyloid. Lamellar edge appearing as a sterile strip, composed of ellipsoid to elongate, inflated cells (30‒60 × 15‒20 µm), filamentous hyphae 3‒5 µm wide, irregularly arranged or running parallel to lamellar edge. Pileipellis 70‒160 µm thick, 2-layered; suprapellis, non- or slightly gelatinized, composed of thin-walled, colorless, clavate terminal cells 130‒300 × 20‒25 µm, mixed with filamentous hyphae 4–8 µm wide; subpellis composed of undifferentiated, filamentous hyphae 3–5 µm wide; vascular hyphae scarce. Volval remnants on pileus composed of longitudinally arranged elements, periclinal orientation: filamentous hyphae abundant, 3–6 µm wide, colorless, thin to slightly thick-walled, branching; inflated cells abundant, subglobose to ellipsoid, 30–60 × 25–35 µm, colorless, thin to slightly thick-walled, terminal; vascular hyphae rare. Outer part of volval limb on the stipe base composed of longitudinally arranged elements: filamentous hyphae abundant, 5–7 µm wide, colorless, thin to slightly thick-walled, branching; inflated cells abundant, subglobose to ellipsoid, 25–60 × 20–40 µm, colorless, thin to slightly thick-walled, terminal; vascular hyphae rare. Stipe trama composed of longitudinally arranged, long clavate terminal cells 170–230 × 15–30 µm; filamentous hyphae scattered to abundant, 4–8 µm wide; vascular hyphae scarce. Clamps absent in all parts of the basidioma.

Habitat:—Solitary or in a small group of four to five individuals, on the ground in woodland and gallery forests, associated with Berlinia grandiflora or Isoberlinia doka (Fabaceae) and Uapaca guineensis (Phyllanthaceae) .

Distribution:—Currently known from Benin, and Togo.

Toxicity:—Absence of toxins (α-amanitin, β-amanitin, phalloidin, and phallacidin) shown for JEIC0595 by Codjia et al. (2022) and for SYN5016 (type specimen) by results presented here.

Additional specimen examined:— TOGO: KARA REGION: Bafilo, 09°20’ 59”N, 01°16’00”E, gallery forest of Bafilo , 08 July 2019, Jean Evans I. Codjia, JEIC0595 (UNIPAR).

Figures

FIGURE 3. Basidiomata of Amanita stubbosa. a. in Benin (SYN5016, holotype); b. in Togo (JEIC0595). Scale bars: 1 cm. Photos by: Codjia J.E.I. and Yorou N.S.

FIGURE 4. Microscopic structures of Amanita stubbosa (holotype SYN5016). A. Young and mature basidia with subhymenium. B. Basidiospores. C. Crushed tissue of volval remnants from the pileus. D. Longitudinal section of the outer layer of the volval limb from the base of the stipe. Scale bars = 10 µm. Drawings by: Codjia J.E.I.