Sangre de gradoCroton lechleri

Did you know?

• Sangre de grado and sangre de drago are both Spanish for "dragon's blood", after the red latex that runs from the cut bark^{[1, 2, 6]}.

• Proanthocyanidins make up as much as 90% of the dried latex^{[1, 2, 4]}.

• The latex is gathered from cuts in the bark, much as rubber is tapped^{[1, 2]}.

• The name "dragon's blood" is shared by red resins from plants on other continents, including the dragon trees of Socotra and the Canary Islands and rattan palms of Southeast Asia^{[7, 8]}.

• The ancient Greeks, Romans and Arabs all valued the Old World's dragon's blood, and it was later used to color varnishes and lacquers, including the varnish on violins^{[7, 8, 10]}.

• The tree was named in 1866 by the botanist Johannes Müller Argoviensis, who had named huanarpo macho the year before^{[3, 9]}.

Origins and history

Sangre de grado is a fast-growing tree of the western Amazon^[2]. It grows on the low mountain slopes where the Andes drop into the Amazon basin, from Colombia and Ecuador south through Peru to Bolivia^{[1, 3]}. The botanist Johannes Müller Argoviensis gave it its scientific name in 1866, in the section on the spurge family that he wrote for de Candolle's great encyclopedia of plants, the Prodromus^{[3, 9]}.

The tree is known for what happens when its bark is slashed. A thick latex seeps out, dark red like blood^{[1, 4]}, and it can be gathered from cuts in the trunk much as rubber is tapped^[2]. That latex gave the tree all of its names: sangre de grado and sangre de drago in Spanish, dragon's blood in English^{[1, 2, 6]}. In the upper Amazon it has two everyday traditions. A little is diluted in water and taken by mouth, and a little is rubbed onto the skin, where it dries into a protective seal^{[1, 2]}.

Europe already knew a "dragon's blood" long before anyone tapped a Croton tree. The name belonged to the red resin of dragon trees and rattan palms, valued by the ancient Greeks, Romans and Arabs and later used to color varnishes^{[7, 8, 10]}. Today the Amazonian latex has become a trade good in its own right: it is one of the few Peruvian plant products marketed worldwide and is exported to North America and Europe^{[4, 5]}.

Traditional uses

Wherever the tree grows, its latex has two traditional uses: a little is taken in water, and a little is spread on the skin^{[1, 2]}.

• Digestive comfort

  In the upper Amazon a small amount of the latex is traditionally stirred into water and taken by mouth for digestive comfort.*^{[1, 2, 4]}

• A film on the skin

  Rubbed onto the skin, the red latex dries into a thin film, a use recorded wherever the tree grows.^{[1, 2]}

• Antioxidant compounds

  The latex provides naturally occurring antioxidant compounds.*^{[1, 4]}

Plant compounds

Sangre de grado latex is remarkably rich in proanthocyanidins, which make up as much as 90% of its dry weight^{[1, 2, 4]}. It also contains the related catechins catechin, epicatechin, gallocatechin and epigallocatechin^{[1, 4]}, an alkaloid called taspine^{[1, 2, 4]} and a lignan called 3',4-O-dimethylcedrusin^{[1, 4]}.