carpogonium

< /ˌkɑr pəˈgoʊ ni ə/.

1. the one-celled female sex organ of some red algae, that, when fertilized, gives rise to the carpospores.

noun plural -nia (-nɪə)

1. the female sex organ of red algae, consisting of a swollen base containing the ovum and a long neck down which the male gametes pass