What is the name of the female structure that holds the ovum during the gametophyte stage?

The archegonium is the structure that specifically holds the ovum in female gametophytes, particularly in non-flowering plants like mosses and ferns. It plays a crucial role in the reproductive process by providing a protective environment for the developing egg cell. The archegonium not only serves as a place for the ovum but also facilitates fertilization by capturing sperm released by male gametophytes. This structure has a unique shape, often resembling a flask, which helps to protect the ovum until fertilization occurs.

The antheridium, on the other hand, is responsible for producing and releasing sperm cells, not eggs, and therefore does not hold the ovum. The sporangium is involved in the production of spores rather than gametes and does not relate directly to the ovum. A capsule typically refers to the part of the plant that releases spores from the sporangium, further distancing it from the reproductive functions of gametophytes. Thus, the archegonium is accurately identified as the female structure involved in holding the ovum during the gametophyte stage.