The Antheridium reference article from the English Wikipedia on 24-Apr-2004
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Antheridium

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Antheridium is the sterile tissue that surronds some organisms' sperms. It is present in lower plants, but absent in gymnosperms and angiosperms. Many ascomycetes, oomycetes and algae also have antheridia during their reproductive stages.

It may be unicellular or multicellular.

In moss, it is propped up by antheridiophore.

Its female counterpart is the archegonium.

Angiosperms have anthers, which contains sperms inside pollens.