Fastigiatine, C19H28N2O, is a minor component of the alkaloids of Lycopodium fastigiatum R. Br. collected in New Zealand. Its structure and relative configuration have been resolved by an X-ray analysis of the free base. The pentacyclic ring system of fastigiatine has not been previously observed in the Lycopodium family of alkaloids or elsewhere. A proposal is presented for its derivation from the tetracyclic flabellidane ring system that is widely distributed among Lycopodium species. The mass spectrum and the 13C and 1H nrnr spectra of fastigiatine are discussed.