Rhodocybe mellea var. depressa M.D.Xavier, Silva-Filho & Wartchow
- Dataset
- GBIF Backbone Taxonomy
- Rank
- VARIETY
- Published in
- (2022). In Xavier, Silva-Filho, Wartchow & Baseia, Phytotaxa 438(2): 92.
Classification
- kingdom
- Fungi
- phylum
- Basidiomycota
- class
- Agaricomycetes
- order
- Agaricales
- family
- Entolomataceae
- genus
- Rhodocybe
- species
- Rhodocybe mellea
materials_examined
Type: — BRAZIL. Paraíba, Mamanguape, Reserva Biológica Guaribas, SEMA II, 23 July 2019, F. Wartchow, FW 08 / 2019 (holotype UFRN-Fungos 3386!; isotype JPB) Diagnosis: — Rhodocybe mellea var. depressa is distinguished by its depressed pileus; the presence of abundant and conspicuous sclerobasidia; small, flexuous-cylindrical pseudocystidia; pileipellis a smooth two-layered cutis; sandy soil habitat; and unique nuclear ITS and LSU sequences. Description: — Basidiomata collybioid (Fig. 2 a). Pileus 13 − 35 mm broad, convex with a depressed center, becoming plane and depressed, brownish orange (OAC 729), paling to yellowish orange (OAC 791); surface dry, hygrophanous; margin entire to slightly sulcated, decurved to straight, sometimes lobed; context fleshy, 1 mm thick, cream (OAC 791), unchanging. Lamellae adnexed with a decurrent tooth, moderately close to close, cream-orange (OAC 717); 2 − 4 mm broad, margin slightly eroded to wavy, concolorous with sides; lamellulae of varying lengths. Stipe 21 − 30 × 2 − 7 mm, equal to slightly enlarged at the base, terete when young, becoming compressed, sometimes slightly flexuous, cream-orange (OAC 717); surface dry, smooth to slightly pruinose; consistency cartilaginous; context solid, fibrous, dark cream (OAC 793); spore print not obtained; odor and taste not determined. Basidiospores 5.2 − 6.5 × 4.1 − 5.4 (5.8 ± 0.30 × 4.7 ± 0.28 μm), E = (1.05) 1.12 − 1.38, Q = 1.25, n = 60 / 2, subglobose to broadly ellipsoid, very rarely globose in profile view, angular in polar view with 7 – 9 angles, undulate-pustulate in all views, lacking a suprahilar plage, thin-walled, hyaline (Figs. 3 b – 4 a). Basidia 22.4 − 30 × 7.4 − 8.1 μm clavate, 4 - spored, thin-walled, hyaline, some with yellowish contents in KOH 5 %; sterigmata 4.5 − 5 μm long; sclerobasidia abundant, 4 - spored, broadly clavate, 23.6 − 34.4 × 5.1 − 8.1 μm, with walls up to 1.2 μm thick (Figs. 3 a, c; 4 b). Pleurocystidia as pseudocystidia 26.5 − 41 × 5.2 − 7.3 μm, originating from the subhymenium, mostly not conspicuously projecting from hymenium, flexuous-cylindrical with rounded to aculeate apex, thin-walled, with pale yellow amorphous contents in KOH 5 % (Figs. 3 a – 4 c). Lamellae edge mixed composed of a few basidia and abundant pseudo-cheilocystidia, similar to the pseudo-pleurocystidia. Subhymenium ramose. Lamellar trama regular, composed of cylindrical hyphae, 4.1 − 7.3 μm wide, thin-walled, hyaline; oleiferous hyphae present, abundant. Pileus trama subregular, composed of cylindrical hyphae, 3.3 − 6.1 μm wide, hyaline, thin-walled and smooth; oleiferous hyphae present, abundant, 2.3 − 3.7 μm wide. Pileipellis a cutis composed of two layers, golden yellow in KOH 5 % (Fig. 3 d): suprapellis as a more separate layer with cylindrical entangled periclinal hyphae, thin-walled, smooth, and cylindrical-clavate terminal hyphae with rounded to inflated apex, 2.5 − 3.1 μm wide (Fig. 4 d); subpellis a layer with strongly entangled periclinal hyphae, thin-walled and smooth. Stipitipellis a cutis of parallel hyphae, 3.6 − 6.4 μm wide, thin-walled to slightly thick-walled, and smooth. Caulocystidia absent. Clamp connections absent in all examined tissues. Etymology: — The name ‘ depressa ’ comes from the Latin and refers to the depressed pileus. Habitat: — Saprotrophic, gregarious, growing on sandy soil among leaf litter. Coastal tableland landscape with Brazilian Savanna (Cerrado) vegetation (Fig. 2 b). Distribution: — Known only from the type locality. Material examined: — The type.