Pollen Morphology of Nepenthes khasiana hook. f. (Nepenthaceae), An Endemic Insectivorous Plant from India

The pollen morphology of Nepenthes khasiana (the pitcher plant) from India, was investigated using both light microscopy and scanning electron microscopy. This was to investigate fine details that may contribute to the taxonomic characterisation of species, as well as to utilise the knowledge of its morphology in order to correlate it with Bornean Nepenthes species. The size of the tetrad is the defining feature. The pollen grain is non-aperturate, the sexine is spinuliferous and thicker than the nexine. The study indicates that the species is similar in shape, aperture and ornamentation, and can be discriminated by the size of the tetrad, the length of the spines and the exine thickness. The size of the tetrad (30.7 µm) is closer to two Bornean species such as N. rafflesiana and N. mirabilis (30.5 and 31.0 µm respectively). These observations will be helpful in morphotaxonomy for accurate identification. This will help in finding these taxa from modern and sub-surface soils in order to study the present status of pollen preservation and decipher the palaeovegetation and past climate of the region.