We isolated six bases from Th. minus, of which base (II) is new for the genus. Three bases were isolated from Th. foetidum, of which thalflavine is new for this species. The combined alkaloids from the corms of Colchicum speciosum Stev. were separated into fractions of strongly basic, weakly basic, and neutral substances. A chloroform extract of the weakly basic compounds was treated and chromatographed on alumina to yield four individual compounds. One of them (Rf 0.83), with composition C28H31O5N, mp 192-194°C, [α]D -42° (c 0.26; chloroform), mol. wt. 461, was identified as a new tropolone alkaloid speciosamine (I) by color reactions and spectral characteristics (UV, IR, PMR, 13C NMR). A previously unknown alkaloid (I) with composition C19H27O4N, mp 201-202°C, [α]D +10°, isolated from the epigeal part of Merendera jolantae E. Czernjak, was determined to be trigamine N-oxide based on spectral data and chemical reduction to trigamine.