1) Fungus genus 2) Genus omphalotus 
Omphalotus is a genus of basidiomycete mushroom formally described by Victor Fayod in 1889. Members have the traditional cap and stem toadstool form. They are saprobic, and grow in clumps on trees. The best known and type species is the jack-o`-lantern mushroom (Omphalotus olearius). Species of Omphalotus, which are poisonous, have been mistaken ....
[n] - a genus of mushrooms with a depressed disc in the cap
genus Omphalotus noun a genus of mushrooms with a depressed disc in the cap