AP BIOLOGY

Detailed explanation-1: -The leaves of Acacia nilotica and Acacia seyal contain tannins (11.80% and 6.30%, resp.).

Detailed explanation-2: -The bark of Acacia mearnsii De Wild. (black wattle) contains significant amounts of water-soluble components, known as “wattle tannin”, which has been used for producing tanned leather for more than one hundred years and for the manufacture of water-resistant and structural wood adhesives for more than fifty years.

Detailed explanation-3: -Other cultures from antiquity obtained tannins from willows (Salix spp.), quebracho (Scinopsis balansae), sumac (Rhus spp.), maples (Acer spp.), wattle (Acacia spp.), eucalyptus (Eucalyptus spp.), and red mangrove (Rhizophora spp.).

Detailed explanation-4: -Tannins, a group of bitter and astringent compounds, can be found abundantly in nature. They’re present in the wood, bark, leaves and fruit of plants as various as oak, rhubarb, tea, walnut, cranberry, cacao and grapes. Perhaps most importantly, they’re also found in wine.

Detailed explanation-5: -The best known families of which all species tested contain tannin are: Aceraceae, Actinidiaceae, Anacardiaceae, Bixaceae, Burseraceae, Combretaceae, Dipterocarpaceae, Ericaceae, Grossulariaceae, Myricaceae for dicot and Najadaceae and Typhaceae in Monocot.