Marasmiellus

Marasmiellus is a genus of fungi in the family Omphalotaceae. The widespread genus, circumscribed by American mycologist William Murrill in 1915, contains over 250 species. The name comes from the Greek marasmus meaning wasting.

== Morphology and life cycle == The morphology of Marasmiellus has received little attention compared to other genera of Omphalotaceae, mainly due to their uncolorful pileus, small basidiocarps, and little variation in morphological characters. These factors complicate delimitations of species within this genus. Species of Marasmiellus have prostrate and diverticulate hyphae, which have no clear orientation. However, it has been observed that other hyphae can aggregate in fascicles and be radially oriented. Furthermore, cheilocystidia arise from horizontal hyphae and are frequently embedded in the hymenium, often being prostrate. Some species of Marasmiellus use basidiospore germination, and distinguishing different genera based on reproduction would depend on the speed of germination. During germination spores of Marasmiellus tend to disperse in dilution platings. Some species are tetrapolar. Additionally, no bipolar or amphithallic taxa in this genus have been reported, which is unexpected, as this mating behavior is common for tropical agarics, by allowing rapid colonizations. Their basidiocarps are collybioid or omphalioid and they have a white spore print. The cutis consis of a pileipellis, which sometimes transitions into a trichoderm, either with or without Rameales-structure.