Pantheon Magazine accepts poetry submissions for some of its ‘open prompts’ (http://pantheonmag.com/submissions/open-prompts/). The current prompt accepting poetry is ‘NYX’. Copied from the website: ‘NYX, also known as Nux, Nox or simply Night is a primordial Greek goddess who personifies the essence of night and darkness. She is the ancient goddess of Night-hence the meaning of her name. She is considered to be one of the most powerful divine beings who was born of the giant cosmic being, Chaos. She is often depicted as a great black winged spirit or riding in a chariot, trailing stars and bringing the night. Submissions open December 1st 2014 and close April 30th 2015′
Visit the Pantheon Magazine website and read the submissions and open prompts criteria carefully, as they are very detailed. http://pantheonmag.com/submission-guidelines/