Affinities of Lupinus prunophilus Jones and L. ammophilus Greene (Papilionaceae)

Abstract

The confused taxonomic history of prunophilus (Papilionaceae) is discussed and its affinities with the morphologically similar L. ammophilus and other putative relatives within the L. ornatus complex and morphologically similar complexes are elucidated. Chemosystematic evidence of alkaloid comparisons support the orthodox morphological, ecological, and geographical distribution data indicating the distinction of the two species; alkaloids lend a diagnostic marker to L. prunophilus. These data are correlated with previous evolution studies in concluding that L.. prunophilus was derived from the California epicenter in a manner similar to that proposed for other members of the L. ornatus complex and most North American lupines, whereas L. ammophilus was derived from the southern Rocky Mountains, being related more closely to the United States east coast L. perennis complex and the Mexican L. madrensis complex. The taxonomy of the genus (Papilionaceae) is generally thought to be in a more chaotic state than most other groups of plants. This is partially attributed to the extreme plasticity of the species (Cox 1970) and partially because of insufficient study. While several taxonomists have attempted to describe and attach epithets to every variant lupine population (e.g., Smith 1927), others have lumped large numbers of divergent taxa (Phillips 1955; Hitchcock et al. 1961). Many lupine descriptions are so vague and the taxonomic treatments disagree so tremendously that one is generally in doubt as to the identity of the species in hand. This largely accounts for the reason for so many lupine specimens, some dating back to the mid 1800's, labeled only Lupinus sp. or are grossly misidentified. Insight is gained into the parameters of variation and affinities of the species by monographic studies where geographic distribution is plotted in conjunction with and as a test for morphological, ecological, and chemical data. I developed a special interest in prunophilus Jones and in its relationship to L. ammophilus Greene while monographing the 1 Study conducted at Division of Biological Sciences, University of Missouri, Columbia, Missouri 65201.