Pollen tube
WordNet
noun
(1) (botany) a slender tubular outgrowth from a pollen grain when deposited on the stigma for a flower; it penetrates the style and conveys the male gametes to the ovule
WiktionaryText
Noun
- the tube that develops from the wall of a pollen grain and, in seed plants, provides a passage through which the male nuclei reach the embryo sac to effect fertilization