The authors wish to express their appreciation to G. Agati for the
use of the CNR-IFAC Jasco UV/VIS Spectrophotometer.
The results presented in this paper are part of the research
project ICCOG “Identification and characterization of nettle and
Spanish broom clones for textile and phytotherapic sectors”
financed by Tuscany Region and the research project PRIN2008
“Medical and dyeing-plants natural extracts: characterization and innovative poly-use of nettle, daphne, lavender and chestnut
tannins” financed by the Ministry of Scientific Research.