Carpogonium

The carpogonium (plural carpogonia) is the female organ in the red algae (Rhodophyta) which have a highly specialized type of reproduction. It contains the reproductive nucleus. It may contain a number of cells usually without chloroplasts. It shows an elongated process which is the receptive organ for the male gametes.^[1][2]

Collema crispum A, Carpogonium, c, with its trichogyne t. B, Apex of the trichogyne with the spermatium, s, attached.

It gives birth to the carpospores.^[3][4]

It may also have hairlike structures called trichogynes which receive sperm before fertilization takes place.^[5]