Antheridium (ăn' ther-ĭd' ĭ-ŭm). The male organ of plants. Within it are produced the sperms or their equivalents, which fertilize the female cells or eggs. The antheridium varies in structure in different groups of plants, being for the most part a single cell in the Thallophytes, and a several to many-celled structure in the higher groups. It is important to note that the antheridium holds no relation to the anther, the structure in the flower which produces pollen, for the anther is not a male organ. To avoid this confusion it has been proposed to change the name antheridium to spermary.
