<em>Comatricha nigra</em> is among the more widely distributed species in the genus <em>Comatricha</em>, with documented records from Asia, Europe, North America, and South America. It belongs to the class Myxomycetes, order Stemonitidales, and is recognized by its dark, stalked sporangia with a distinctive capillitium. The species grows on decaying wood, bark, and moist plant debris in forest habitats across its broad geographic range. As with all plasmodial slime molds, <em>C. nigra</em> undergoes a life cycle that includes a motile plasmodial feeding stage and a reproductive sporangial stage. The feeding plasmodium consumes bacteria, fungal spores, and organic particles, playing a role in nutrient cycling and decomposition. The global distribution of <em>C. nigra</em> reflects the capacity of slime mold spores to disperse over long distances via wind currents. No quantitative biological metrics are recorded, and the species has not been assessed by the IUCN.