1. The leaves of L. tulipifera L. have yielded lirinine N-oxide and a new amorphous base with the composition C20H23O3N, [α] D 25 -52.9° (c 0.171; chloroform), M+ 325 (mass spectrometrically). 2. On the basis of its UV, IR, and mass spectra and chemical transformations, the structure of 2,5,6-trimethoxyaporphine has been established for the new alkaloid. © 1975 Plenum Publishing Corporation.