A re-examination has been made of the leaf and seed alkaloids of Lupinus cosentinii Guss. (incorrectly designated L. pilosus, L. varius or L. digitatns in earlier literature). The previous findings of epilupinine (1), epilupinine N-oxide (4) and multiflorine (2) in both leaf and seed have been confirmed but, in contrast to the earlier reports, it has been shown that the leaf alkaloid consists largely of epilupinine esters. The esterifying acids are acetic acid, unidentified acids related to truxinic or truxillie acid, ferulic acid and p-coumaric acid and the rhamnosides of ferulic acid and p-coumaric acid. The acetate ester of epilupinine N-oxide and mixed esters of 13-hydroxymultiflorine are also present in the leaf. Both leaf and seed contain a new tricyclic alkaloid CuHsNAO which is shown to have structure 19 based on the rhombifoline skeleton. © 1979, American Chemical Society. All rights reserved.