Rhodophana flavipes T.J. Baroni, Daniëls & Hama, 2017

Daniëls, Pablo P., Baroni, Timothy J., Kluting, Kerri, Bergemann, Sarah, García-Pantaleón, Felix Infante, Barage, Moussa & Ibrahim, Dahiratou, 2017, A new species and a new combination of Rhodophana (Entolomataceae, Agaricales) from Africa, Phytotaxa 306 (3), pp. 223-233 : 227-230

Rhodophana flavipes T.J. Baroni, Daniëls & Hama sp. nov. ( Figs. 3–13 )

Mycobank: MB# 811694

Diagnosis:—Characterized as a species of Rhodophana by the strongly undulate-pustulate subamygdaliform basidiospores with cyanophilic spore walls that are angular by 7–11 facets in polar view and the abundant clamp connections present on most hyphae of the basidiomata, differing from other species in Rhodophana by the erect pyramidal reddish brown squamules on the pileus surface when young, the pileus becoming orange-brown and strongly sulcate with age and the yellow stipe that produces thick cord like rhizoids at the base which are covered with acicular crystals, and by the distinctive rbp2 (KC816984) and tef1 (KC816891) DNA sequences.

Etymology:— “ flavipes ” refers to the yellow color of the stipe.

Holotype:— NIGER. Tillabéri Region: Department of Say, Tamou Commune, W National Park, General Seyni Kountché I, elev. 236 m, 12°26’52”N, 02°26’09”E, 14 September 2009, in bushy savanna with Combretum micranthum G.Don , C. nigricans Leprieur ex Guill. & Perr. , C. glutinosum Perr. ex DC. and Guiera senegalensis J.F.Gmel , in leaf litter and woody debris, leg. O. Hama, M. Barage & D. Ibrahim, Hama 259 (COFC-F 5050).

Isotype:—CORT and Université Abdou Moumouni, Niamey ( Niger).

Description:— Pileus dark reddish (9C5—Dull Red to 9D5—Rosewood) at first when moist, becoming more brownish (7D7–8—Burnt Sienna or Brick Red or 7E6–8—Agate) with loss of moisture, especially over the disc and with margin becoming a much paler buff orange (5B4—Grayish Orange to 5A3—Pale Orange) or eventually light yellow or cream color (4A3–4) in dry conditions, slightly hygrophanous with reddish brown fibrils and squamules contrasting with the paler ground color, 30–80 mm broad, at first convex, then becoming plano-convex with the disc broadly depressed, surface uniformly covered with dark brownish silky appressed fibrils and squamules, squamules often erect, pyramidal and/or squarrose, obvious, especially over the disc, surface opaque, smooth at first, becoming subsulcate or strongly sulcate with expansion and age, margin incurved becoming decurved, fleshy. Flesh white or pale peach (5A2—Orange White), 2 mm thick, unchanging when exposed. Lamellae at first pale yellowish (4A2– 3—Cream), but soon light orange or pale peach or orange buff (5–6A2—Orange White or 5–6A3—Pale Orange), becoming darker and more flesh colored (7A–B3—Pale Red or Greyish Red), eventually darker brownish orange (7C5–6) with age, adnexed, broadly adnexed or somewhat sinuate, seceding, subdistant, thick, broad (3–4 mm deep), edge concolorous, even becoming eroded. Stipe pale yellow (4A3—Cream) or light yellow (4A4—Light Yellow), becoming darker (5B4—Greyish Orange) and also from handling (reddish or reddish brown bruising of fibrils on the stipe), 4–10 mm broad, 40–65 mm long, equal, cylindrical, straight or sometimes curving, surface smooth but innately fibrillose splitting, hollow, with thick white rhizomorphs (0.5 mm in diam.) at base. Odor herbaceous. Taste not distinctive.

Basidiospores (6.4–) 7.2–10.5 (–11.3) × (4.8–) 5.6–6.4 (–7.2) μm (x = 8.2 ± 1.16 × 5.97 ± 0.47 μm, Q = 1.13–1.83, Qm = 1.4 ± 0.18: n=61/3), subamygdaliform or ellipsoid in profile view, ellipsoid or obovate in face view, minutely angular in polar view with 7−11 facets, strongly undulate-pustulate all over, walls evenly cyanophilic, inamyloid. Basidia mostly 4-sterigmate, some 2-sterigmate, narrowly clavate, 26−31.6 × 8.8−10 μm. Hymenial cystidia absent. Lamella trama stramineous in 3% KOH, composed of parallel, cylindrical hyphae, 6−14 μm in diam and mostly short in length, 20−50 μm, also with repository hyphae filled with shiny yellow or golden pigments and scattered through the trama. Pileipellis yellowish ochre or yellowish orange in 3% KOH, composed of repent, cylindrical hyphae, 2.4−7.2 μm in diam, not encrusted, hardly differentiated from context except by the narrower width of the hyphae, also with scattered groups of erect fascicles of agglutinated cylindrical hyphae that are slightly broader than those of the rest of the pellis, 8−14 μm in diam. Pileus context hyaline, composed of inflated, interwoven hyphae (4−)8−18 μm in diam, also undulating refractive repository hyphae filled with diffuse yellow pigment, 3−12 μm in diam, occasionally branched, scattered through the context. Stipitipellis near the apex of the stipe a hyaline or pale stramineous layer of repent, cylindrical hyphae, 2.4−4.8 μm in diam, producing scattered clusters of erect fascicles of agglutinated cylindrical hyphae similar to those of the pileipellis. Clamp connections present and obvious in all tissues. Rhizomorphs composed of cylindrical interwoven hyphae, 3−16 μm diam, external layer of hyphal walls covered with easily dislodged long, acicular crystals that are often fractured into smaller blunt end pieces, individual crystals 2−10−60 × 0.5−2.0 μm, small bacilliform crystals also present. Repository hyphae scattered or abundant in the pileus context and lamella trama, yellow or golden yellow in 3% KOH, mostly cylindrical, occasionally irregularly swollen, 3−18 μm in diam, sometimes septate, sometimes branched, without clamps.

Habit, habitat and fruiting period:—Single or gregarious in small numbers, saprotrophic on rich organic litter areas, notably in the gallery forests with Cola laurifolia Mast. , Mitragyna inermis (Willd.) K.Schum. and Diospyros mespiliformis Hochst. ex DC. present.

Additional specimens examined:— NIGER. Tillabéri Region: Department of Say, Tamou Commune, W National Park, General Seyni Kountché II, elev. 254 m, 12°27’06,3”N, 02°25’38,9”E, 28 August 2008, in open savanna with plant debris under Isoberlinia doka Craib & Stapf and Acacia ataxacantha DC. , leg. O. Hama, M. Barage & D. Ibrahim; Hama 105 (COFC-F 5431). Tillabéri Region, Department of Say, Tamou Commune, W National Park, close to the Mékrou River on the border with Benin, elev. 216 m, 12°15’17”N, 02°23’24”E, 6 August 2010, riparian forest with Cola laurifolia and Mitragyna inermis , in leaf litter and woody debris, leg. O. Hama, P. Daniëls, M. Barage, D. Ibrahim & M. Rosas; Hama 315 (COFC-F 5030); same location, 8 September 2012, leg. O. Hama; Hama 591 (COFCF 5554). Tillabéri Region, Department of Say, Tamou Commune, W National Park, close to the Mékrou River on the border with Benin, elev. 332 m, 12°15’16’’N, 02°23’22’’E, 29 August 2010, riparian forest, on rotten wood, leg. O. Hama, M. Barage & D. Ibrahim; Hama 434 (COFC-F 5029). Tillabéri Region, Department of Say, Tamou Commune, W National Park, close to the Mékrou River on the border with Benin, elev. 218 m, 12°15’18’’N, 02°23’25’’E, 15 August 2012, riparian forest with Kigelia africana (Lam.) Benth. and Mitragyna inermis , in clay-sandy soil with leaf litter and woody debris, leg. O. Hama, Hama 526 (COFC-F 5552); same location, Hama 527 (COFC-F 5553).

Figures

FIGURES 3−6. Basidiomata of Rhodophana flavipes. Figs. 3−4 are young fresh samples of Hama 259 (Holotype). Figs. 5−6 represent the older mature stages of the basidiomata with faded colors of the pileus, Hama 434. Scale bar = 10 mm. Photos by O. Hama.

FIGURES 7−13. Basidiospores of Rhodophana flavipes (Hama 259, Holotype). Fig. 7: Various views of basidiospores and strongly developed ornamentation. Fig. 8: Polar view of a single basidiospore. Fig. 9: SEM image of a single spore in profile view. Fig. 10: Microscopic image of a pyramidal scale of the pileipellis. Fig. 11: Clamp connection on hyphae of stipe basal cords. Fig. 12-13: Crystals on the hyphae of the stipe basal cords. Scale bars = 10 μm except Fig. 9 bar = 1 μm. Photos by T. J. Baroni.