Sentence:  The staminate willow catkins , then , provide their visitors with both nectar and pollen ; a marvelous arrangement , for it provides exactly what the bee queens need to make their beebread , a combination of honey and <WSD>pollen</WSD> with which the young of all species are fed . 
Meaning of the word marked with <WSD> tags:  the fine spores that contain male gametes and that are borne by an anther in a flowering plant