ABSTRACTIntroductionMany species in the Lupinus genus are poorly defined morphologically, potentially resulting in improper taxonomic identification. Lupine species may contain quinolizidine and/or piperidine alkaloids that can be acutely toxic and/or teratogenic, the latter resulting in crooked calf disease.ObjectiveTo identify characteristic alkaloid profiles of Lupinus sabinianus, L. garfieldensis and L. sericeus which would aid in discriminating these species from each other and from L. sulphureus.Methods and materialsQuinolizidine and piperidine alkaloids were extracted from herbarium specimens and recent field collections of L. sabinianus, L. garfieldensis and L. sericeus. The alkaloid composition of each species was defined using GC‐FID and GC‐MS and compared using multivariate statistics.ResultsEach of the three species investigated contained a diagnostic chemical fingerprint composed of quinolizidine and/or piperidine alkaloids.ConclusionThe alkaloid profiles of Lupinus sabinianus, L. garfieldensis and L. sericeus can be used as a tool to discriminate these species from each other and L. sulphureus as long as one considers locality of the collection in the case of L. sabinianus. Published 2011. This article is a US Government work and is in the public domain in the USA.