The seeds of Medicago sativa (alfalfa) have previously been shown to contain other bases besides stachydrine. One of these bases has now been isolated and found to be a homologue of stachydrine for which the name homostachydrine is suggested. (—)-Homostachydrine is shown to be identical with the (—)-methyl betaine of pipecolic acid. The synthetic racemate of the betaine of pipecolic acid has similar properties to homostachydrine, and their infrared spectra and X-ray powder diagrams are identical.