Arcyria cerradensis Agra, L. H. Cavalcanti & Dianese, 2018

Agra, Leandro A. N. N., Cavalcanti, Laise H. & Dianese, José C., 2018, A new species of Arcyria from the Brazilian Cerrado, Phytotaxa 344 (3), pp. 283-286 : 283-284

Arcyria cerradensis Agra, L. H. Cavalcanti & Dianese sp. nov. Figure 1 .

Mycobank: MB821314

Sporocarps stalked, erect, solitary or gregarious, 1–2 mm tall. Sporotheca cylindrical to ovoid with attenuated apex and base, vivid yellow (v.Y 82) to brilliant yellow (brill.Y 83). Hypothallus individual, discoid, moderate reddish orange (m.r O 37). Stalk cylindrical, erect, 0.6–1 mm long, longitudinally striated, deep orange yellow (deep OY 69) at the base to vivid yellow (v.Y 82) at the top, brilliant orange (brill. O 49) in transmitted light, filled with spore-like cells; spore-like cells 11–19 μm diam., subglobose to slightly angular. Peridium single, membranous, brilliant yellow (brill. Y 83), pale yellow (p.Y89) in light microscope (LM), remaining at the base as a calyculus. Calyculus saucer-shaped and plicate, with irregular warts in the inner surface. Capillitium tubular, seldom branched and poorly anastomosed, firmly attached to the calyculus border, brilliant yellow (brill. Y 83), light yellow (l. Y 86) by LM; tubules 1.7–2.4 μm diam. with a diameter of 3.0–5.0 μm when included the ornamentations. Ornamentations consisting of continuous superficial irregular lines and protrusions distributed in regular fashion, often as rings or half rings. Spores free, globose, vivid yellow (v. Y 82) in mass, yellowish white (y Gy 93) to translucent in LM, 6–7 (7.5) μm diam., minutely but densely warted.

Type:— BRAZIL. Mato Grosso: Vila Bela da Santíssima Trindade, Gallery Forest at Parque Estadual da Serra do Ricardo Franco, Fazenda Pelicano, 14° 49’ 58,7” S, 60° 11’ 11,7” W, 22 February 2014, on carbonized trunk, L. Agra PPBio 136 (holotype, UB Mycol. Coll. 23529).

Etymology:— cerradensis (Latin) , refers to the Cerrado Biome, the unique Brazilian savanna where the specimen was collected.

Distribution:— only from type locality.

Within the genus Arcyria , 13 species show yellow pigments ( Poulain et al. 2011, Lado et al. 2017). Included the new record, all 14 yellow species can be identified by the key below.

Figures

FIGURE 1 (A–F). Arcyria cerradensis Holotype (UB Mycol. Coll. 23529). A. Yellow sporocarps on rotten wood. B. Sporocarp. C. Stalk showing characteristic spore-like structures. D. Plicate calyculus showing warts at the inner surface. E. Capillitium and spores in light microscopy. F. Capillitum threads seen in SEM. G. Spore surface seen in SEM. Scale Bars: A=3mm, B=1mm, C= 20 μm, D-F=10 μm, G=1 μm.