Metatrichia floripara (Rammeloo) Rammeloo, Icon. Mycol.

Treviño-Zevallos, Italo, García-Cunchillos, Iván & Lado, Carlos, 2021, New records of Myxomycetes (Amoebozoa) from the tropical Andes, Phytotaxa 522 (3), pp. 231-239 : 233

Metatrichia floripara (Rammeloo) Rammeloo, Icon. Mycol. 1, pl. 47 (1984), Fig. 2

Sporocarps scattered, stalked, 1.8–2.7 mm in total height. Sporotheca globose to piriform, 0.7–0.8 mm diam., yellowish brown (74. s. y Br) to blackish. Hypothallus membranous, light brown (57. l. Br). Stalk cylindrical, erect to slightly curved, sometimes two sporocarps appear joined by their stalks, 0.8–1.2 mm long, longitudinally striate, brownish (57. l. Br), reddish brown (40. s r Br–44. d. r Br) to deep orange (51. deep O) by transmitted light, filled with dirt particles at the base. Peridium double, thick, persistent; outer layer leathery and homogeneous, orange yellow (70. l. OY–71. m. OY) by transmitted light; the inner layer attached to the outer layer, thin, membranous, pale yellow (89. p. Y) by transmitted light, inner surface with warts forming a reticulate pattern; dehiscence petaloid, the top half breaks into 4–6 involute lobules, showing the capillitium and spore mass. Columella absent. Capillitium tubular, elastic, light yellow (87. l. Y) to orange yellow (71. m. OY) by transmitted light, tubules 4–5.5 µm diam., flexuous, rarely branched, without attachments to the peridium, decorated with 2–3 prominent spirals, smooth, free ends blunt or short-pointed, 10–14 µm long. Spores free, orange yellow (67. brill. OY–70. l. OY) in mass, yellowish (101. l. g Y) by transmitted light, subglobose, 12–13.5 µm diam., with prominent warts, showing as a border of 1 µm thickness in optical section.

Specimen examined: — PERU. Huancavelica: Huaytara, Pilpichaca, route PE-28 A, km 208, 10 km W of Licapa , 4020 m, 13º24’18”S, 74º53’54”W, 23 April 2017, dead leaves of Puya raimondii, Lado 25103 (MA-Fungi 96291) .

Comments: —Third record in the world, the second in South America, and the first for Peru. The previous collections of the species were found at 2400 m.a.s.l. in mountain rain forest ( Rammeloo 1981) and 831 m. a.s.l. in Araucaria moist forest ( De Lima & Cavalcanti 2016), however, our specimen was found in a very different environment, at 4020 m.a.s.l., in puna vegetation, on the sheaths of the dead leaves of Puya raimondii , an endemic and endangered plant of the Tropical Andes. This species is characterized by the dark leathery peridium and the petaloid dehiscence of the sporotheca, the capillitium ornamented with smooth spirals and short pointed ends, 10–14 µm long. It is similar to M. floriformis (Schwein.) Nann. -Bremek. (1985:127) in morphology, but the capillitium of M. floriformis presents long-tapering free ends, 25–40 µm long, while that of M. floripara has blunt ends. It also resembles M. vesparia (Batsch) Nann. -Bremek. ex G.W. Martin & Alexop. (1969:143), but is easily distinguishable by the secondary spines on the spiral capillitium ornamentation, whereas there are smooth spirals in M. floripara .

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.