Akademik

(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

ˈpollen tube 7 [pollen tube] noun (biology)

a tube that grows when ↑pollen lands on the ↑stigma (= a part of the female organ) of a flower to carry the male cell to the ↑ovule (= the part that contains the female cell)