 Both come from the same species of tree ("Caesalpinia echinata"), but pernambuco, used for higher-quality bows, is the heartwood of the tree and is darker in color than brazilwood (which is sometimes stained to compensate).Pernambuco is a heavy, resinous wood with great elasticity, which makes it an ideal wood for instrument bows.Horsehair is stretched out between the two ends of the bow.