Morphometrics
We studied vegetative and reproductive traits of 76 herbarium specimens (60 males and 16 females), previously used to delimit taxa boundaries in other Dioscorea species (e.g., Viruel et al., 2010), using a 150 mm calliper, a stereomicroscope and ImageJ 1.52a (Schneideret al., 2012). Traits were measured and treated independently for male and female individuals (Supplementary Data Table S2). Pollen grains were sputter coated with platinum and examined using a Hitachi S4700 cold field emission scanning electron microscope (SEM) at 2kV (Hitachi High-Technologies Corporation, Tokyo, Japan).
A value of >0.7 Pearson correlation was used as a threshold to exclude correlated variables from the analysis. The normality Kolmogorov-Smirnov test with Lilliefors correction and the homoscedasticity Levene’s test were applied to the variables following a normal distribution. Subsequently, comparisons among taxonomic units identified in phylogenomic analyses (see Results) were conducted using Kruskal-Wallis and Bonferroni post-hoc tests. Statistical analyses were performed using ‘nortest’, ‘Hmisc’, ‘corrplot’, ‘PerformanceAnalytics’ and ‘car’ packages in in R v.4.0.5 (R Core Team, 2022).