Gametangium is a term commonly used in biology to describe a specialized structure found in fungi, algae, and some plants where gametes are produced. The word gametangium is derived from the Greek words gamete, meaning "husband" or "wife," and angioun, meaning "vessel." However, there are several other synonyms that can be used to refer to this structure, depending on the organism being studied. For example, in fungi, the term antheridium is used to describe the male gametangium, while the female gametangium is called the ascogonium. In algae, gametangia can be referred to as spermatangia and carpogonia, while in plants, the male gametangium is called the pollen and the female gametangium is called the ovule.