Two new species of Perichaena (Myxomycetes) from arid areas of Russia and Kazakhstan

Abstract

Two new myxomycete species from dry steppe and desert communities of the Caspian Lowland (Russia) and central Kazakhstan are described and illustrated. They are placed tentatively within genus Perichaena, which does include species with a reduced capillitium and single-layered peridium. Both species were found repeatedly in moist chamber cultures; P. heterospinispora appeared on leaf litter and twigs, whereas P. polygonospora occurred on leaf litter and weathered dung of rodents. Both species have spore ornamentation that is unique for members of genera Licea and Perichaena. The spore ornamentation of the first species includes scattered large, pyramid-like spines 0.9-1.2 microm high that sometimes have enlarged ends. Among these spines the spore surface is covered by evenly and densely distributed warts that are visible only by SEM. The second species is characterized by angular spores with a coarse network of rounded ridges. The areas among these ridges bear scattered composite warts 0.3-0.5 microm high that sometimes coalesce to form clusters but more often are distributed evenly and densely and are visible only by SEM. The stability of the taxonomic characters of both species was confirmed by several collections from different regions obtained in 2 y. The morphology of the fructifications of the two myxomycetes was examined with both scanning electron and light microscopy, and micrographs of all relevant features are presented.

Perichaena longipes, a new myxomycete from the Neotropics

“…The sporotheca of P. longipes is similar to those of many other stipitate species of Perichaena, excluding the sporocarp of P. polygonospora, which is much smaller (0.05-0.1 mm), lacks a capillitium and has a unique polygonal spore shape (Novozhilov et al 2008). The sporocarp of P. longipes is light yellow to tan, darker at the base, and the peridium is smooth, sometimes with a weak iridescence (FIG.…”

“…Most other stipitate species of Perichaena are darker and/or do not have a smooth peridia surface. For instance, the sporotheca of P. papulosa is brownish orange and has an apical wart (Liu et al 2007), P. polygonospora is buff or buffyellow and covered with orange-brown protuberances (Novozhilov et al 2008) and P. calongei is yellow to dark brown, with dark lines marking the edges of the peridia plates of dehiscence (Lado et al 2009). Another stipitate species, P. areolata, is not light yellow similar to P.…”

“…It is assigned to the genus Perichaena on the basis of the thick and persistent peridium along with the presence of a well-developed, irregular, branching and ornamented capillitium lacking spiral bands, the surface of which is covered by pits when viewed by SEM (Novozhilov et al 2008, Lado et al 2009, Poulain et al 2011. The bright yellow spores also validate the placement of P. longipes into the higher-level, bright-spored clade of the myxomycetes (Fiore-Donno et al…”

Occurrence and distribution of Perichaena (Trichiaceae, Myxomycetes) in the Brazilian Northeastern Region

“…For some authors, such as Eliasson (1977;, Keller & Eliasson (1992) and Novozhilov et al (2008), species with capillitium scanty or absent indicate a possible affinity between Perichaena and Licea; however, this relationship was not supported in recent molecular phylogenetic analyses that showed the genus Perichaena to be monophyletic (Fiore-Donno et al 2013). Hypothallus conspicuous.…”

“…Capillitium abundant or scanty, filaments hollow, nonbirefringent, simple or branched, almost smooth, warted or spiny, often constricted. Spores in mass yellow, orangecolored or ochraceous, yellow by transmitted light, globose, subglobose to ovate, rarely polygonal, warted, spinose or reticulated (Lister1925; Martin & Alexopoulos 1969;Novozhilov et al 2008;Poulain et al 2011;Novozhilov & Stephenson 2015).…”