Estimations of ploidy
The differences in genomic histories between M. spicata andM. × rotundifolia can potentially be explained by
differences in ploidy (Chambers & Hummer, 1994; Harley & Brighton,
1977). The ploidy estimates using HMMploidy were variable and somewhat
consistent with previously reported chromosome counts. Although our
estimates are uncertain, they suggest that specimens morphologically
assigned as M. spicata are polyploids and those assigned asM. suaveolens are diploids (Table 1). The estimates forM.longifolia and M. × rotundifolia are variable (Table 1).
Generally, specimens morphologically assigned as M. longifoliaand not inferred as admixed were estimated to be diploids whereas
specimens morphologically assigned as M. × rotundifolia were
estimated to be “likely polyploids” or “polyploids” (Table 1).