Luminis Glacies, from Latin 'luminis' (light) and 'glacies' (ice), is a bioluminescent fungus thriving in cold cave microhabitats (0-10°C). It has translucent, gelatinous, funnel-shaped fruiting bodies (10–30 cm) with pale icy blue caps, wavy margins, and striated surfaces, accented by soft orange luminescence along decurrent, closely spaced gills and at the cap-stipe junction. Luminescence (450–495 nm) arises via luciferin-luciferase enzymatic reactions typical of the Arboreal Aurantica cluster. Anchored to detritus-rich substrates by stout fibrous stipes, L. Glacies belongs to Armeniaceae, genus Luminis, order Agaricales. Passive spore dispersal occurs through gravity and air currents. It forms extensive mycelia, playing a saprotrophic role in nutrient recycling and supporting cave microecological balance, representing a rare but stable subterranean fungal niche.