We are studying alkaloids in flowers of Arundo donax cultivated in the Tashkent Botanical Garden. Total alkaloids were obtained by usual CHCl3 extraction of dried and ground plant material moistened with aqueous ammonia (5%). Five decantations were performed. The combined CHCl3 extracts were condensed and treated with H2SO4 solution (5%). Alkaloids were extracted by CHCl3 from the acidic solutions after they were made basic with conc. aqueous ammonia. The extracts were dried and condensed to afford a mixture of bases (0.042%). Chromatography (TLC) of the total alkaloids identified three alkaloids with Rf values 0.1, 0.6, and 0.7 (TLC, Al2O3, C6H6:CH3OH, 9:1) and 0.75, 0.80, and 0.85 (CHCl3:CH3OH, 9:1). Treatment of the total alkaloids with acetone separated crystals with mp 134-135°C, which were identified by Rf and mixedmelting point as the known alkaloid donaxine [1, 2]. The mother liquors from donaxine were chromatographed over a column of Al2O3. Elution with CHCl3 separated crystals with mp 178-180°C (acetone) that were identified as the alkaloid donaxaridine [1, 3] by mixed-melting point and comparison of spectra. Signals for C atoms in the 13C NMR spectrum of donaxaridine were previously incorrectly assigned [3]. Therefore, we studied its PMR and 13C NMR spectra. The magnitude of the chemical shifts and the nature of the substitution enabled the signals to be grouped into aromatic and aliphatic parts. The HMBC spectrum of donaxaridine exhibits the following important correlation peaks: CH3/C-5; H-4a,5a,CH3/C-2; H-4a,b,NH2,OH,H-3′,5′/C-1′; H-4a,b,5a,NH2′,OH/C-3; H-4′,5′,NH2/C-6′; NH2-2′/C-4′; H-4′/C-2′; H-5′/C-3′; NH2,H-3′/C-5′. Continued elution of the column with CHCl3 gave fractions that afforded a base with mp 148-149°C that was identified as arundinine [4]. Thus, flowers of Arundo donax contain three pure bases that are described in the literature: donaxine, donaxaridine, and arundinine. These alkaloids were isolated from the flowers of this plant for the first time.