Diderma laiseae Moreira, Leonardo-Silva & Xavier-Santos, 2025

Moreira, Izabel Cristina, Leonardo-Silva, Lucas & Xavier-Santos, Solange, 2025, Diderma laiseae (Didymiaceae, Physarales), a new species of Myxomycetes from Brazil, Phytotaxa 682 (2), pp. 192-196 : 193

Diderma laiseae Moreira, Leonardo-Silva & Xavier-Santos , sp. nov. Fig. 1

MycoBank: MB856462

Diagnosis:— Diderma laiseae differs from other species of the genus by its sessile sporophores with prominent ridges, a rough surface and spores globose to subglobose, strongly warty, marked by prominent and irregular lines.

Type:— BRAZIL. Goiás: municipality of Silvânia, Floresta Nacional de Silvânia , 16º 38ꞌ 30.0ꞌꞌ S,48º 39ꞌ 02.5ꞌꞌ W; 900 m a.s.l., 30 March 2012, I. C. Moreira & S. Xavier-Santos ( SXS5113 ), Holotype ( HUEG9367 ).

Etymology:— laiseae is named in honor of Dr. Laise de Holanda Cavalcanti, in recognition of her great contributions to the study of Myxomycetes in Brazil.

Description:— Sporophores crowded, formed by several small sporocarps, sessile, marked with ridges that give it a polygonal appearance, up to 0.4 mm high, 0.3–0.5 × 0.4–0.52 mm diam. Hypothallus white (1BA), well-developed, persistent, usually covered with lime incrustation. Peridium double, with scattered deposits of lime granules, outer layer greyish white (1BA), with prominent, robust transverse and longitudinal ridges that give it a rough appearance, reticular dehiscence caused by the rupture of ridges. Columella greyish yellow (3C3), globose, calcareous. Capillitial smooth to wrinkled, brown, without calcareous intercalations, simple to branched with free ends. Spore-mass yellowish brown (5F8). Spores (8.3–)9.3–11(–12.7) × (10.2–)11.2–13.3(–13.8) µm [Q = (1) 1.1–1.3(–1.4); Qm = 1.2; N = 30], globose to subglobose, violet-brown, with prominent, irregular lines that sometimes confer an angular shape, strongly warty; in SEM the warts can be described as rounded to lanceolate, occasionally bifurcated and arranged irregularly.

Habitat:— Sporophores growing on decaying wood and on insect remains (coleoptera) in the mesophilic forest.

Known distribution:— Known only in Brazil Central, in the state of Goiás, in a Cerrado ecosystem.

Figures

FIGURE 1. Diderma laiseae. A, B. Sporophores growing on insect remains (A) and decaying wood (B). C. Entire sporophore in lateral view. D. Prominent ridges on the surface and the reticular opening. E. Columella. F, G. Capillitium under light microscopy (F) and under scanning electron microscopy (G). H, I. Spores under light microscopy (H) and SEM (I). Scale bars: A, B = 1 mm, C‒E = 0.5 mm, F = 5 µm, G‒I = 2 µm.