The Sporangiophores are assembled into Cones or Strobili . Equisetum is Homosporous and the spores are green . They germinate to produce a protonema which eventually forms a three dimensional, photosynthetic gametophyte . Antheridia develop first on slightly elevated lobes of the gametophyte. The archegonia are produced later in the vicinity of the basal Rhizoids .
Fertilization occurs when flagellated sperm swim to the egg.
Embryo development is immediate and Exoscopic . The embryo contains Root and Shoot Apical Meristems and a Foot. Lab Activities Observe living specimen if available. Make note of the nodes and internodes as well as the origin of Roots . Make sure you identify the leaves.