A crystalline alkaloid (C₁₅H₂₆N₂O) which accompanies (-)-β-isosparteine in specimens of the plant, Lupinus sericeus Pursh, grown in southern Utah, has been shown by chemical evidence to be either 7-hydroxy-β-isosparteine or the 8-hydroxy isomer. The 7-hydroxy structure is favored by the chemical evidence and independently confirmed by X-ray crystallographic investigation. Specimens of dried, above-ground parts of the plant, Lupinus sericeus Pursh, collected near Salina, Utah, yielded (-)-β-isosparteine as the principal alkaloid. The chemical proof of its structure and stereochemical relationship to (+)-sparteine have been previously described. The absolute configuration of (-)-β-isosparteine (I) follows from our earlier work showing the identity of the configurations of C-7 and C-9 in (-)-β-isosparteine and in (+)-sparteine, and from the interconversions of Okuda, Tsuda, and Kataoka.