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).