Local ecotype seed cultivated in agricultural holdings, belonging to the family Papillonaceae; genus Phaseolus; species Phaseolus coccineous.
The plant, with a voluble stalk, is a creeping plant with a luxuriant flowering: the flowers are white and many. The dry pod, with an average length of 10-12 cm, carries big-size almond-shaped seeds. Fagiolone has been cultivated since ancient times in Aniene Valley, in particular in the Municipalities of Vallepietra and Filettino. There are several oral witnesses and photos documenting the historical presence of this cultivation. The seed is guarded by local old farmers handing it down from generation to generation.