ericaceae: heathers
ericales: Ericaceae; Clethraceae; Diapensiaceae; Epacridaceae; Lennoaceae; Pyrolaceae; Monotropaceae
pollen tube: (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