The Black Iris Club is a chain of Night World clubs located throughout the US. The clubs are usually in urban areas, in less savoury parts of town, located in old, non-conspicuous buildings, marked by a black iris symbol. The symbol is usually something that will be noticed by Night People, but overlooked by humans, such as graffiti outside the Club's entrance. The Black Iris Club utilises a black iris as its symbol, which is also the symbol of lamia. Members of the Club often wear clothing or jewelry with a black iris, such as Ash Redfern, who wears a T-shirt with a black iris print.
Lamia seem to be the primary owners and members of the Club, though other kinds of Night People are also allowed to join. However, it is mentioned that some Night People, particularly werewolves, are generally looked down upon. Werewolves are often employed as bouncers to guard the entrances to the clubs, making sure no humans stumble upon the place by mistake. It is unclear how one becomes a member exactly. If a human were to somehow find their way into a Club, then they will most likely be killed by the members to protect their secret, as demonstrated when Gillian Lennox attempted to enter a Black Iris Club and was mistaken for a human.