This is a chestnut extract, produced in Italy. This is not the same as the Horse Chestnut Bark, which gives more orange hues and has a lesser tannin content. 
 
Castanea sativa, sweet chestnut, is a deciduous tree growing up to 30m. The trees are grown in traditional orchards in the Mediterranean, where they are grown for nuts and timber. The extract is a convenient by-product of the leftover bark. The flowers are rich in pollen and nectar and beneficial for honey production, you will find many beehives between the trees in the grove.
 
Chestnut extract can be used as a brown/red/golden shade dye depending on the mordant, or as a tannin base for grays with post mordant ferrous sulfate. Tannin content; 75-77%
 
Dye samples in pictures;
Top row; 15% ATF, second row no mordant and third row PostMordant FE