Omphalotus subilludens is a fungus species in the genus Omphalotus. The type collection was found by Murrill on July 26, 1944 in Gainesville, Florida. It has also been recorded from Texas. Atromentin and thelephoric acid are chemical compounds found in cultures of C. subilludens. Atromentin is an effective anticoagulant, and similar in biological activity to the well-known anticoagulant heparin. Atromentin also possesses antibacterial activity, inhibiting the enzyme enoyl-acyl carrier protein reductase (essential for the biosynthesis of fatty acids) in the bacteria Streptococcus pneumoniae.