GervãoStachytarpheta jamaicensis

Did you know?

• In English, blue porterweed is also called Brazilian tea^{[3, 4]}. Its dried leaves have been brewed as a tea on their own and even blended into ordinary tea^{[4, 5]}.

• Fittingly for a plant called porterweed, a tea of the leaves of its Brazilian relative is said to look like porter, the dark beer, and to foam in the same way^[5].

• In Florida, where it is native, blue porterweed is a favorite of butterfly gardeners. Its flowers feed many kinds of butterflies and draw hummingbirds, and its leaves feed the caterpillars of the tropical buckeye butterfly^{[4, 6]}.

• Only two or three flowers open at a time on each spike, and each one lasts a single day, but a spike keeps flowering for weeks^[4].

• Its slender flower spikes grow 4 to 12 inches (10 to 30 cm) long, and its names include rat tail in English and queue-de-rat in French^{[3, 4]}.

• In Florida, look-alike non-native porterweeds are sometimes sold in place of the native blue porterweed^[6].

Origins and history

Blue porterweed is a branching, half-woody herb. It may sprawl low along the ground or grow upright to about 3 to 5 feet (1 to 1.5 m), with toothed, oval leaves^{[4, 5, 6]}. Its small flowers, deep blue to purple with a white throat, open along long, slender spikes, and in warm climates it blooms nearly all year^{[4, 6, 7]}. It grows on beaches and coastal dunes, along sandy roadsides and in open ground^{[5, 6]}.

Carl Linnaeus first named the plant Verbena jamaicensis, placing it among the vervains, and in 1804 the botanist Martin Vahl moved it to Stachytarpheta^{[1, 4]}. Its native range runs from Florida and the Caribbean through Mexico and Central America to Colombia, Venezuela, the Guianas and northern Brazil, and it has since spread through the tropics worldwide^{[1, 4, 5, 7]}. Its close relative S. cayennensis is native from Mexico to Argentina, including Peru and all of Brazil^{[2, 5]}.

In Brazil, gervão, also called gervão-roxo ("purple gervão"), is a familiar folk herb, most often taken as a tea of the dried leaves^{[5, 8]}. In the Caribbean, blue porterweed goes into bush tea: on the island of St. Croix the fresh leaves are brewed as a cooling tonic^[4]. In parts of the tropics the tender shoot tips are also used as a pot herb, and the leaves are cooked with other vegetables^{[4, 5]}.

Traditional uses

Clinical studies of gervão in people are still few, but its traditional use is rich, from Brazilian leaf tea to Caribbean bush tea.

• Gervão leaf tea

  In Brazil, a tea of the dried leaves is a traditional drink for the stomach and liver. Gervão supports healthy digestion.*^{[5, 8]}

• Tinctures and syrups

  Brazilian folk practice also prepares gervão as a tincture or a syrup.^[8]

• A Caribbean bush tea

  On St. Croix, fresh leaves are brewed into a bush tea and drunk as a cooling tonic.^[4]

• A leafy green

  The tender shoot tips are used as a pot herb, and the green leaves are chopped and cooked, alone or with other vegetables.^{[4, 5]}

Plant compounds

Gervão contains naturally occurring iridoids, notably ipolamiide, along with flavonoids, tannins and an essential oil^{[4, 5]}. It also contains stachytarphine, a compound that takes its name from the genus, and verbascoside, scutellarein and ursolic acid^[4].