Pollination. An unidentified species of bee pollinating the flower of the sweetbriar, Rosa rubiginosa (also known as eglantine). The bee's proboscis can reach deep into flowers to suck up the sugary nectar. In obtaining its meal this bee has inadvertently powdered itself with pollen, which it may later deposit on another plant of the same species, ensuring cross-pollination. The orange lump on the bee's hind leg is a pollen basket. The compacted pollen inside it is an important source of protein that the bee will carry back to its nest.