Pau d'arcoHandroanthus impetiginosus

Did you know?

• "Pau d'arco" is Portuguese for "bow stick": the wood was prized for hunting bows^{[3, 4]}.

• Ipê, its Brazilian name, comes from the Tupi for "thick-barked tree"^{[9, 10]}.

• The tree drops its leaves just before it flowers, so it blooms in pink and purple on bare branches, roughly June to September in the south^{[3, 9, 10]}.

• Ipê, the timber of pau d'arco's genus, Handroanthus, is so dense that most pieces sink in water. It was used for the boardwalk at New York's Coney Island, where it is said to have lasted 25 years before it needed replacing^[11].

• Brazilians name their ipê trees by flower color: pau d'arco is ipê-roxo, the purple ipê, while its relatives include ipê-amarelo (yellow) and ipê-branco (white)^{[7, 12]}.

• Since 2024, international trade in ipê timber has been controlled under CITES to protect wild trees^{[11, 13]}.

Origins and history

Pau d'arco is a deciduous tree that can reach 30 meters, with a trunk up to 80 centimeters (about 2.5 feet) across, leaves divided like the fingers of a hand, trumpet-shaped flowers and exceptionally hard, durable wood^{[2, 3, 9]}. It grows from Mexico to northern Argentina, in rainforest and in the drier forests and savannas of central Brazil^{[1, 9]}. In Brazil alone its range runs from Maranhão in the north to Rio Grande do Sul in the far south^[9].

Its botanical name has changed with science. For most of the twentieth century it was known as Tabebuia, from a Tupi-Guarani word said to mean "stick" or "floating wood"^[10]; in 1970 the Brazilian botanist Mattos placed it in a new genus, Handroanthus, and in 2007, after DNA studies, botanists confirmed that the dense-wooded trees rich in lapachol belong together there^{[1, 14, 15]}. Through all the renaming, the peoples of South America kept one use constant: the inner bark, simmered into a strong tea^{[7, 8]}. In the herb trade the name pau d'arco is also used for the inner bark of a few close relatives, notably Tabebuia heptaphylla^{[4, 7]}.

Traditional uses

Clinical studies in people are still few and small^{[3, 7]}, but pau d'arco has a long and widespread tradition across South America.

• An inner-bark tea

  The inner bark is traditionally simmered in water to make a strong tea, called a decoction.^{[7, 8]}

• Immune support

  Pau d'arco supports healthy immune function.*^[3]

• Healthy-looking skin

  A strong tea of the inner bark, or a poultice, has traditionally been applied to the skin. Pau d'arco supports healthy-looking skin.*^{[3, 8]}

• Digestive comfort

  A decoction of the inner bark has traditionally been taken for the stomach, to support digestive comfort.*^[8]

Plant compounds

Pau d'arco's best-known compounds are naphthoquinones, especially lapachol and beta-lapachone^{[3, 7]}. The inner bark also contains anthraquinones, flavonoids, iridoids and lignans^{[3, 16]}.