Submitted to: Biochemical Systematics and Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2001
Publication Date: 3/5/2002
Citation: GARDNER, D.R., RALPHS, M.H., TURNER, D., WELSH, S. TAXONOMIC IMPLICATIONS OF DITERPENE ALKALOIDS IN THREE TOXIC TALL LARKSPUR SPECIES (DELPHINIUM SPP.). BIOCHEMICAL SYSTEMATICS AND ECOLOGY. 2002. Interpretive Summary: Three of the tall larkspur species which cause significant poisoning problems on rangelands of the Western U.S. were examined using morphological, genetic, and chemical methods to define the taxanomic classification scheme used for these plants. In this paper the chemical profile of the plants was used to provide specific groupings and separation nof the different species. A total of 163 individual plants were collected from 18 different locations and upon analysis four distinct groups could be identified. The statitical groups agreed best with the historical classification of Ewan (1945). These data support the classification of Delphinium glaucum, D. barbeyi, and D. occidentale as distinct species and suggest that a possible hybrid is more similar to D. occidentale than D. barbeyi.
Technical Abstract: The diterpene alkaloid content was used to assess the chemical taxonomic diversity in three larkspur species. Samples (n = 163) were collected from 18 different locations in five western states, extracted and analyzed for diterpene alkaloids using electrospray mass spectrometry. The data was statistically analyzed using canonical discriminant analysis and analysis of variance. Delphinium glaucum samples were easily grouped and were significantly different from all other groups (P < 0.005) for two compounds. Delphinium barbeyi and D. occidentale were found to be distinct groups, but more closely related. Samples representing a putative hybrid between D. barbeyi and D. occidentale were found to be closely related to D. occidentale, but were significantly different from all other groups. These data support the classification of Delphinium glaucum, D. barbeyi, and D. occidentale as distinct species and suggest that a possible hybrid is more similar to D. occidentale than D. barbeyi.