Four known alkaloids, lycorine (I), tazettin (II), nerinine (II), haemanthidine (N) and a new alkaloid C₁₆H₁₉O₄N , m.p. 201~202° (decomp.), were isolated from Zephyranthes candida HERB., Amaryllidaceae (Japanese name "Tamasudare") which has been cultured in Japan as decorative plants.Physical constants of the new alkaloid which is designated zephyranthine are as follows : [α]24 -43.17° (c=0.47, CHCl3); IR ν_max^KBr cm⁻¹: 3470 (-OH), 1040, 945 (methylenedioxy group); pKa' 9.20 in water; UV λ_max^ECH 291 mp (log ε 3.71). The alkaloid contains one methylenedioxy N-methyl, O-methyl or olefinic unsaturated functional groups. It gives diacetate, C₂₀H₂₃O₆N , m.p. 68~70° and acetate hydrochloride, C₂₀H₂₃O₆N·HCl , m.p. 294~295°(decomp.).