Palynology is a fascinating science with a multidimensional approach covering almost all branches of botanical sciences. It is segregated into many sub-branches viz., aeropalynology, palaeopalynology, melissopalynology, forensic palynology etc. Pollen morphology is also used as an important tool for plant identification and classification. Here, I will concentrate my discussion on the taxonomic use of pollen morphology with especial reference to the family Ericaceae. The cosmopolitan family Ericaceae is the 8th largest family of angiosperms. It comprises eight subfamilies, twenty tribes, ca. 125 genera and 4100 species. In the recent phylogenetic classification of Ericaceae (Kron et al. 2002), the relationship among the subfamilies is well defined, but relationships among the tribes are not fully understood. Therefore, it appeared timely to study in detail the pollen morphology of Ericaceae with the hope of identifying new characters that could add new insight into future analyses of the family. For this palynological investigation, 275 taxa of 270 species representing 57 genera and 6 subfamilies were studied with light (LM) and scanning electron microscopy (SEM), and 31 species with transmission electron microscopy (TEM). The systematic significance and evolutionary trends of palynological characters have been discussed in the light of the recent phylogenetic classification of the Ericaceae. Pollen grains are dispersed as monads, tetrads or polyads, commonly of medium (30 – 50 m) size and 3-colpor(oid)ate. Viscin threads are present only in a few genera of the subfamily Ericoideae (Bejaria and other eight genera). With SEM, exine sculpture varies from finely verrucate to psilate, and twelve major exine sculptural types have been recognized. Two dichotomous keys to the pollen of Ericaceae were prepared with the characters observed under LM, and exine sculpture with SEM. With TEM, the exine structure of ericaceous pollen is basically the same, and composed of ectexine; tectum, columellae and foot layer, and endexine. Two unique exine structures, granular columellae and canalized tectum, were observed in the monad pollen of two Erica species, E. barbigera and E. recurvifolia, and the canalized tectum also observed in Rhododendron japonicum and Oxydendrum arboreum. The TEM observations were also found useful to confirm some critical palynological observations with LM and/or SEM: heterodynamosporus tetrads, different types of exine sculpture, tetrads without septa, presence of pollenkitt and pollenkitt ropes, causes of pollen shrinkage, and identification and realignment of taxa.

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