Equisetum– gametophyte
The younger gametophytes bear antheridia and archegonia (see Raven 7th p. 403; 8th, p. 425). In this particular specimen the antheridia (Anth) are well-developed.
In this specimen the egg within the archegonium of the older gametophyte (Gam) was fertilized, and the young sporophyte (Sp) is developing from it. Observe the diagram in Raven 7th p. 404-405; 8th, p. 426-427 and be sure you understand the life history of Equisetum.
GENUS
STEM and LEAVES
STROBILUS
GAMETOPHYTE