Luminaria Nimbus, named from Latin for “light cloud,” is a bioluminescent fungus with ethereal, cloud-like fruiting bodies featuring delicate, translucent, ruffled caps with iridescent folia. Caps display reticulate, honeycomb textures from pale yellow/deep orange centrally to opalescent white edges. Gills are absent, replaced by a smooth hymenial surface continuous with a slender, semi-translucent stipe. Fruiting bodies reach 0–15 cm in height and weigh up to 15 g. Bioluminescence in the blue spectrum (450–495 nm) originates mainly at cap margins via luciferin-luciferase reactions. Endemic to tropical caves, it thrives in 10–20°C humid conditions on decaying leaf litter and woody detritus, serving as a critical decomposer. Belonging to Agaricales, Omphalotaceae, genus Luminaria, it disperses spores by gentle air currents aided by cap movement. Its mycelium sustains cave nutrient cycling. Due to narrow habitat and distribution, L. Nimbus is endangered, requiring conservation.