Geographical History and Infraspecific Morphological Variation of American Cow-Wheat (Melampyrum lineare; Orobanchaceae)




Oldham, Karoline

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The wildflower American cow-wheat (Melampyrum lineare Desr.) is the sole North American species of an otherwise Eurasian genus. There are four purported varieties of M. lineare, though it has not been thoroughly determined whether they merit designation as distinct taxonomic entities. Further, the evolutionary history of M. lineare has been poorly studied in light of this species’ geographic isolation from the rest of its genus. The goal of this study was to reevaluate and revise the infraspecific taxonomy of Melampyrum lineare and to test hypotheses regarding the evolutionary history of this species using comparative genetic methods. The four purported varieties of M. lineare do not represent truly distinct taxonomic entities based on morphological data. Instead, morphological variation occurs along a continuum with no clear divisions between the putative varieties. Results from comparative genetic methods provide mixed support for the competing hypotheses of European versus Asian ancestry for the sole North American species in Melampyrum.



Melumpyrum lineare, Orobanchaceae, Biogeography, Infraspecific morphology, Scrophulariaceae, Botany