The New Student's Reference Work/Archesporium

Ar'chespo'rium. In plants a developing spore-vessel sets apart certain cells from all others to produce the spores. The first cells which can be distinguished in this way, and which give rise to all of the tissues which produce spores, are known collectively as the archesporium. The archesporium is a prominent feature in the history of the sporangia of all higher groups of plants.