Haematoxylum campechianum

Logwood (Haematoxylum campechianum) is a species of flowering tree in the legume family, Fabaceae, that is native to southern Mexico and northern Central America.It has been and to a lesser extent remains of great economic importance. The modern nation of Belize grew from 17th century English logwood logging camps. The tree's scientific name means "bloodwood" (haima being Greek for blood and xulon for wood).
Logwood was used for a long time as a natural source of dye, and still remains an importance source of haematoxylin, which is used in histology for staining. The bark and leaves are also used in various medical applications. In its time, logwood was considered a versatile dye, and was widely used on textiles but also for paper.The dye's colour depends on the mordant used as well as the pH. It is reddish in an acidic environments but bluish in alkaline ones.