Over 60 compounds are now classified as Erythrina alkaloids, and the structures of most of these have been deduced from a combination of mass spectral fragmentation analysis, H-NMR spectral interpretations, and chemical correlations with alkaloids of known structures. Some “unusual” alkaloids have been obtained from certain Cocculus species and a new, as yet small, subgroup, the Homoerythrina alkaloids, has been recognized. The biosynthetic pathway from tyrosine through the aromatic bases to the erythroidines has been elucidated, and some significant advances have been made in methods of total synthesis. Reviews of the Erythrina alkaloids since 1966 have appeared. Because of the postulated biosynthetic derivation of the Cephalotaxus alkaloids from the Homoerythrina bases, the former, relatively new group is included in the chapter. Anticancer activity has been found in certain members of the Cephalotaxus group, thus the subject has already been reviewed several times. Annual coverage is given to the Erythrina, Homoerythrina, and Cephalotaxus alkaloids in the Specialist Periodical Reports of the Chemical Society. The Erythrina alkaloids are conveniently divided into two main structural groups: the 1,6-diene group and the Δ1(6)-alkene group. The biogenetically important alkaloid erysodienone cannot be classified in this manner. The chapter covers the literature from November 1966 to the end of May 1979. © 1981 Academic Press, Inc.