Abstract
The pollen morphology of the orders Asparagales and Liliales (Lilianae) mostly in Japan including Nartheciaceae was observed by light microscopy for 106 species of 47 genera in 14 families. Pollen grains are monad and vary from 19.2 (Chionographis japonica) to 196.0 μm (Lilium longiflorum) in the longest axis. The grain shape is usually ellipsoidal to spherical, and rarely obtuse tetrahedral (Dianella), tetrahedral spherical (Chionographis), obtuse triangular prismal (some individuals of Tofieldia japonica), or orange segmental (Allium, Nothoscordum). The pollen class is usually 1-sulcate, and rarely inaperturate (Aspidistra, Smilax, Tupistra), omniaperturate (Heterosmilax, Trillium), 2-sulcate (Tofieldia, Uvularia), 4-porate (Chionographis), 1-trichotomosulcate (Dianella), or 2-trichotomosulcate (some individuals of Tofieldia japonica). The sculpture is usually reticulate or perforate, and rarely gemmate, verrucate, clavate, granulate, or echinate. Sulci usually extend to the grains ends without marginal thickenings. The sulcus of some grains has a granulate membrane or an operculum with a sculpturing pattern similar to that of the exine. Pollen grains of the Asparagales and Liliales were classified into 20 types based on these characteristics, and recent classifications of the Asparagales and Liliales were reevaluated based on these pollen types.
