The alkaloidal constituents of Aconitum columbianum Nutt. ssp. columbianum have been investigated. In addition to the known alkaloids cammaconine (12), deltaline (10), dictyocarpine (11), talatizamine (3), and 8-0-methyltalatizamine (7), a new base columbidine (4) has been isolated and its structure elucidated. The structure was derived on the basis of spectral data and chemical correlation with talatizamine. Synthesis of 7 from talatizamine is described and the 13C-nmr spectrum of 14-dehydrotalatizamine has been recorded. Certain 13C-nmr signals for these compounds have been reassigned. © 1985 Japan Institute of Heterocyclic Chemistry. All rights reserved.