<jats:p>The alkaloidal composition in the two title taxa differs only quantitatively. Both contain amurine as the main alkaloid. <jats:italic>P. nudicaule</jats:italic> ssp. <jats:italic>xanthopetalum</jats:italic> contains muramine, protopine and alkaloid PN1 (probably identical with (±)-nudaurine (<jats:italic>Ia</jats:italic>)) as dominant alkaloids; further were isolated amurensine, epialpinine, cryptopine, mecambridine and alpinigenine. Allocryptopine, papaverrubines A, B, D and G, palmatine and coptisine were detected chromatographically. The quaternary alkaloid fraction afforded <jats:italic>cis</jats:italic>-N-methylstylopinium hydroxide (as the iodide <jats:italic>II</jats:italic>) which was isolated for the first time from <jats:italic>P. nudicaule</jats:italic>. In <jats:italic>P. nudicaule</jats:italic> ssp. <jats:italic>album</jats:italic> the alkaloid PN1, epialpinine, amurensine and muramine represented the dominant alkaloids, accompanied with mecambridine, protopine, cryptopine, allocryptopine and alpinigenine. Among the quaternary alkaloids N-methylstylopinium hydroxide was found.