placenta

A membranous vascular organ that develops in female eutherian mammals during pregnancy, lining the uterine wall and partially enveloping the fetus, to which it is attached by the umbilical cord. Following birth, the placenta is expelled.

A similar organ in marsupial mammals, consisting of a yolk sac attached to the uterine wall.

An organ with similar functions in some nonmammalian animals, such as certain sharks and reptiles.

The part within the ovary of a flowering plant to which the ovules are attached.

In zoöl., anat., and medicine: The organ of attachment of a vertebrate embryo or fetus to the wall of the uterus or womb of the female.

In echinoderms, a flat discoidal sea-urchin, as a sand-dollar or cake-urchin: used in a generic sense by Klein, 1734.

[capitalized] A genus of bivalve mollusks, now called Plaruna.

In botany, that part of the ovary of flowering plants which bears the ovules.

The vascular appendage which connects the fetus with the parent, and is cast off in parturition with the afterbirth.