Ordination and Model‐Based Clustering Analyses Highlight Palynological Variation and Patterns in a Comprehensive Pollen Survey of Southern Hemisphere Forget‐Me‐Nots ( Myosotis , Boraginaceae)

The pollen of multiple individuals from 31 ebracteate‐erect and three bracteate‐prostrate taxa of the southern hemisphere forget‐me‐nots ( Myosotis , Boraginaceae, Cynoglossoideae) was investigated using scanning electron microscopy (SEM). The main aims of this study were to complete a pollen survey of all 60 taxa from the southern hemisphere lineage and analyse these data together with previously published data to visualise morphological patterns in the group. For each of 75 individuals of 34 taxa, 18 different morphological characters were observed, described, scored and analysed. Pollen grains are small and heteroaperturate with 8–12 apertures, and are of similar size, shape and exine ornamentation compared to previous studies. Nevertheless, additional variation was found, including a new pollen type. An updated description of southern hemisphere Myosotis pollen is provided. Ordination and model‐based clustering analyses of the final dataset of 12 characters and 231 individuals representing 60 taxa recovered three significant clusters which largely comprised individuals with M. australis type pollen, M. uniflora type pollen, and all other pollen types. The resulting ordination plots of the full dataset data subsets show some structuring by taxonomy and pollen type. The results are interpreted considering previous pollen and phylogenetic studies within the family, subfamily and genus.