The mature antheridium of the genus Riccia is differentiated into the stalk and the body of the antheridium. The stalk has few cells which attaches to the base of the antheridial chamber. The body of the antheridium is oval with a flat base and a conical apex. The body is covered by a sterile jacket which encloses the androcytes. These androcytes on maturity forms the antherozoids.