Culvenor and Smith (1959) isolated only one liquid base, 1-methylenepyrrolizidine, from the seeds of Australian Crotalaria anagyroides and reported total tertiary alkaloid content of 1.50% and N-oxide content of 0.03%. The present work aimed to observe differences in the nature of alkaloids and their N-oxides in the introduced Indian species. Results revealed the presence of senecionine apart from 1-methylenepyrrolizidine. The discovery of senecionine is the first report of a solid base in the trifoliolatae group of the genus Crotalaria and also the first instance of simultaneous occurrence of solid and liquid bases in a member of this genus. The tertiary base content in the Indian species was markedly lower (0.60%) compared to the Australian species (1.50%). The liquid base, identified as 1-methylenepyrrolizidine by its boiling point (72-75℃/36 mm), picrate (m.p. 210-213℃ decomp.), picrolonate (m.p. 172-173℃), specific rotation (-42° in ethanol), Rf value (0.29), and IR/NMR/gas chromatography data matching authentic samples. The solid base, identified as senecionine by its melting point (232-235℃ decomp.), mixed melting point with authentic sample, elemental analysis (C=64.71%, H=7.61%, N=4.80% vs calc. C=64.46%, H=7.51%, N=4.18% for C₁₈H₂₅NO₅), specific rotation (-56.0° in chloroform), Rf value (0.57), IR peak (757 cm⁻¹), and derivatives (picrate m.p. 187-188℃, nitrate m.p. 212-213℃, methiodide m.p. 242-243℃ decomp.). Hydrolysis of senecionine yielded retronecine and senecic acid, confirming its structure.