Morphometrics and redescription of Aphyllon fasciculatum and Aphyllon franciscanum (Orobanchaceae), two widespread but previously conflated species in western North America

We continue the taxonomic reevaluation of Aphyllon sect. Aphyllon by describing a widespread species throughout Western North America previously recognized within a polyphyletic A. fasciculatum. To support our description and revised key, we analyzed fifteen continuous and discrete characters across 156 herbarium specimens and iNaturalist observations sampled from across the geographic range. Principal component and multiple correspondence analyses reveal clear variation in floral characters. Discriminant analyses show that floral color, the calyx cup to calyx lobe ratio, calyx lobe length, and degree of bend in the corolla tube are useful distinguishing features, but not diagnostic in every case.