[Ontogeny of strobili, sporangia development and sporogenesis in Equisetum giganteum (Equisetaceae) from the Colombian Andes].

Studies on the ontogeny of the strobilus, sporangium and reproductive biology of this group of ferns are scarce. Here we describe the ontogeny of the strobilus and sporangia, and the process of sporogenesis using specimens of E. giganteum from Colombia collected along the Rio Frio, Distrito de Sevilla, Piedecuesta, Santander, at 2200m altitude.