Arcyodes incarnata (Alb. & Schwein.) O.F. Cook, 1902

Treviño-Zevallos, Italo, García-Cunchillos, Iván & Lado, Carlos, 2021, New records of Myxomycetes (Amoebozoa) from the tropical Andes, Phytotaxa 522 (3), pp. 231-239 : 232

Arcyodes incarnata (Alb. & Schwein.) O.F. Cook , Science 15: 651 (1902), Fig. 1

Sporocarps grouped to crowded, sessile. Sporotheca subglobose, 0.5–0.8 mm diam., yellowish (86. l. Y–87. m. Y) to light olive brown (94. l. Ol Br). Hypothallus inconspicuous. Stalk absent. Peridium single, membranous, persistent, yellow (86. l. Y–83. brill. Y), sometimes bright and translucent, pale yellow (89. p. Y) by transmitted light, the inner surface with warts and irregular ridges, sometimes with papillae joined in a fragmented net; dehiscence irregular. Columella absent. Capillitium tubular, pale yellow (89. p. Y) by transmitted light, tubules (3–)4–4.5(–5) µm diam., branched and anastomosed, often with irregular swellings, the surface with warts or spinules, sometimes connected by ridges into a reticulum. Spores free, yellow (83. brill. Y) in mass, pale yellow (89. p. Y) to colourless by transmitted light, subglobose, 7–9 µm diam., warted, with groups of more prominent warts.

Specimen examined: — PERU. Junin: Huancayo, route 14B, 10.8 km W of Hacienda Acopalca, 3505 m, 12º00’18”S, 75º09’38”W, 27 April 2017, bark and wood of Eucalyptus globulus, Lado 25434 (MA-Fungi 96589), trunk of Eucalyptus globulus, Lado 25437 (MA-Fungi 96591).

Comments: —First record for the Southern Hemisphere. Associated with vegetation in cultivated areas, mainly the bark and dead wood of Eucalyptus globulus . The species is recognized by its crowded, sessile sporocarps and spiny or warty capillitium. The specimen analyzed agrees with the description of Nannenga-Bremekamp (1991), however, as observed by Zhang & Li (2013), the spores of the collections examined are larger, up to 9 µm vs. 6–8 µm in diameter in Nannenga-Bremekamp (1991).

Figures

FIGURES 1–3. Fruiting bodies of the Myxomycete collections recorded in Peru. 1. Arcyodes incarnata. Heaped sessile sporocarps, with peridium either intact or irregularly broken after dehiscence. Scale bar = 1 mm. 2. Metatrichia floripara. Single sporocarp, long-stalked, and with the peridium partially evanescent after dehiscence. Scale bar = 0.2 mm. 3. Trichia mirabilis. Grouped sessile sporocarps. Scale bar = 0.5 mm.