Scanning electron microscopic studies on pollen from honey. IV: Surface pattern of pollen of Sapium sebiferum and Euphorbia spp (Euphorbiaceae)

Several species of Euphorbia and Sapium plants produce considerable amounts of nectar, which is collected by bees for honey production. In order to identify the nectar source species we used the usual method of melissopalynology (identification of pollen grains by light microscopy) as well as scanning electron microscopic (SEM) studies. Authenticated specimens of pollen were examined in a state of contraction as well as expansion. Four types of exine surface pattern could be distinguished by SEM. E Coerulescens, E ledienii and E tetragona show the same 3 variations in exine structure (type A, B, C). It was therefore not possible to distinguish between these 3 Euphorbia species. However Sapium sebiferum showed a specific pattern and uniformity of exine structure (type D).