What is the role of strobili in horsetail reproduction?

In the reproduction of horsetails (Equisetum), strobili—often referred to as cones—serve as the specialized reproductive structures where spores are produced. These structures are essentially compressed stems that form at the tips of branches.12

The role of the strobilus in the reproductive cycle includes:

• Spore Production: The strobilus contains appendages known as sporangiophores, which bear fingerlike sporangia. These sporangia produce large quantities of homosporous spores.12
• Dissemination: Once mature, the sporangia open to release the spores. The spores possess four ribbon-like appendages called elaters that coil and uncoil in response to changes in humidity, which assists in the effective dispersal of the spores.12
• Structural Variation: Depending on the species, these strobili may be borne on green aerial shoots, on nongreen shoots that later turn green, or on specialized nongreen branches that wither after the spores have been shed.12

Once dispersed, these spores germinate to form the gametophyte phase of the plant's life cycle.12