Pata de VacaBauhinia forficata

Did you know?

• Pata de vaca means "cow's foot" in Portuguese and Spanish. The name describes the two-lobed leaf, which looks like the print of a cloven hoof^{[2, 3, 5]}.

• In Brazil it has another hoof name too: unha-de-boi, "ox's hoof"^{[2, 3]}.

• Its genus, Bauhinia, was named in honor of the Swiss botanists Jean and Gaspard Bauhin, who were brothers^[7].

• A cousin in the same genus, the Hong Kong orchid tree, is the floral emblem of Hong Kong, and a stylized bauhinia flower appears on the Hong Kong flag^[7].

• In Florida and other warm places, pata de vaca is planted as a street and patio tree under the name Brazilian orchid tree, for its showy white flowers^[5].

• In 2009 Brazil's Ministry of Health placed pata de vaca on RENISUS, its national list of 71 plants of interest to the public health system^{[3, 6]}.

Origins and history

Pata de vaca is a tree of the forests of southern South America. It grows as a shrub or small tree, usually up to about 30 feet (9 meters) tall, with leaves 2 to 4 inches long that are cleft into two lobes, and showy white flowers^[5]. Its natural range runs from Bolivia and Paraguay through Uruguay and the south, southeast and west-central regions of Brazil to northern Argentina^{[1, 3]}. It is not native to Peru^{[1, 3]}.

The tree was first described by botanists in 1821^{[1, 2]}. Its genus, Bauhinia, is a large group of trees, shrubs and vines of the tropics and subtropics, many of them grown for their orchid-like flowers^{[5, 7]}. Its best-known names come from the leaf. In Portuguese and Spanish it is pata de vaca, "cow's foot"; in Brazil it is also unha-de-boi, "ox's hoof"; and across southern South America the whole genus is known as "cow's hoof"^{[2, 3]}. In English-speaking gardens it is the Brazilian orchid tree^{[2, 5]}.

The leaf is the part people use. In Brazil, Paraguay, Uruguay and Argentina, the leaves of pata de vaca and several related Bauhinia species are drunk as an infusion or tea, and are also prepared as decoctions and tinctures^{[3, 4]}. The leaves are also added to mate or chimarrão, the region's traditional yerba mate drink, or steeped in alcohol^[3].

Traditional uses

Clinical studies in people are still few, but pata de vaca's traditional use is long and widespread, and it remains a popular plant tea across southern South America^{[3, 4]}.

• Leaf tea

  The leaves are traditionally steeped in hot water as an infusion, simmered as a decoction, or added to mate.^{[3, 4]}

• Healthy blood sugar

  In Brazil and its neighbors, pata de vaca leaf tea is traditionally taken for healthy glucose metabolism.* It helps maintain healthy blood sugar levels already within the normal range.*^{[3, 4]}

• Antioxidant compounds

  The leaf provides naturally occurring antioxidant compounds, mainly flavonoids.*^{[3, 4]}

Plant compounds

Pata de vaca leaf contains many flavonoids, especially flavonoid glycosides, plant compounds in which a flavonoid is joined to one or more sugars^{[3, 4]}. The main one is kaempferitrin, a glycoside of kaempferol, which is found in both recognized subspecies of the tree, subsp. forficata and subsp. pruinosa^[3]. The chemistry of the two subspecies differs noticeably, so the exact profile of a leaf depends on which one it comes from^{[3, 4]}.