On-line Guide to the positive identification of Members of the Cactus Family
khaph on Twitter: "Pfeiffera monacantha ssp kimnachii is one of my favourite cactus to grow as a houseplant. Just one flower on it at the moment but it's very orange. #pfeiffera #lepismium #
Pfeiffera monacantha - Garden.org
Pfeiffera monacantha ssp. monacantha (Ex Lepismium monacanthum) - Foudecactus.com