Lanonia eclipsata (Arecaceae), a new species from northern Vietnam

A new species of Lanonia (Arecaceae, Coryphoideae, Livistoninae) from Tuyen Quang, Vietnam, Lanonia eclipsata sp. nov ., is described and illustrated based on morphological comparisons, molecular phylogenetic analysis, and pollen morphological analysis. L. eclipsata is morphologically most similar to L. dasyantha , but can be distinguished from the latter by its smaller leaves, inflorescences extending beyond the crown, yellowish-green sepals, petals, and rachillae, green immature fruits, and more loosely arranged pistillate flowers on inflorescences and fruits on infructescences. The phylogenetic relationships based on single-nucleotide polymorphisms (SNPs) from genome skimming data provide further support for the recognition of L. eclipsata as a monophyletic clade (BP = 100). Pollen morphology of L. eclipsata and L. dasyantha was investigated and described using a scanning electron microscope (SEM). Six pollen morphological traits of these two species were statistically analyzed using Student’s t -test, five of which showed significant differences. Palynological evidence supports treating L. eclipsata as a distinct species.