Cattleya bowringiana is an easy-to-grow fairly tall bifoliate orchid species that was re-classified as Guarianthe bowringiana a few years ago. It can be referred to by either name.
This plant is a clone of the ‘Blue Angel’ cultivar, a nicely shaped dark-flowered variety that was awarded an HCC/AOS in 1980. The flowers should be identical to those in the picture.
This is a blooming size division that is well-established and bloomed in this 5” pot in October, when the photo was taken.
For more information about C. bowringiana, see http://www.orchidspecies.com/cattbowringia.htm
Plant shown in photo is one of those for sale – others should be similar.