"Palude di San Genuario" is one of the few areas interrupting the continuum of the rice-growing plain of Vercelli. It covers about 426 ha, stretching out from the east to the west, next to an ancient river terrace at the base of which there is the head of some resurgences. For its particular soil features, the area includes agricultural areas that have been historically marginal areas.
The biotope includes ponds dominated by submerged or floating rooted hydrophytes like Utricularia australis, Potamogeton sp., Callitriche sp., Chara sp., but also by sections of water-lily formations with Nuphar luteum presenting silting up strips with halophytes like Phragmites australis, Typha latifolia, Carex sp. Moreover, the site is characterized by a thick network of channels fed also by the waters of the resurgences and connecting with the rice fields and the big irrigation channels. Vegetal formations consisting of aquatic macrophytes are widespread. The arboreal formations, although relict, are represented by well-diversified coenoses characterized by most of the species defining the oak-hornbeam plain woodlands.
The area is the one and only site in Piedmont, and one of the few sites at a national level, where Botaurus stellaris, Ardea purpurea, and Circus aeruginosus nest at the same time: they are species linked to canebrakes of a certain size which are extremely localized in Italy. Ixobrychus minutus also nests here. The site is the wintering site of Egretta alba, as well as a site where several species of the Heron family find food and shelter (Nycticorax nycticorax, Ardeola ralloides, Ardea cinerea, Egretta garzetta, Casmerodius albus). Moreover, Aythya nyroca could find in the area an adequate site for nesting. There is one of the few populations of Emys orbicularis known at a regional level.