The Bursera genus includes trees and shrubs found in arid and semi-arid regions of the Americas, from the southwestern United States to northern Argentina. These plants are recognized for their distinctive features, including aromatic resins and often peeling bark. They thrive in challenging dry tropical and warm temperate forest habitats.
Key Characteristics of Bursera
Plants within the Bursera genus display attributes that enable their survival in dry environments. Many species are deciduous, shedding their leaves during dry seasons to conserve moisture, and often develop thick, gnarled trunks and branches. Their bark is particularly notable, frequently appearing smooth and papery, and often peeling away in thin strips. This exfoliation can reveal underlying layers in vibrant shades of orange, red, or even coppery bronze, contributing to their ornamental appeal.
A defining characteristic is the production of aromatic resins. When bark is cut or damaged, a sticky, fragrant substance oozes out. These resins contribute to their distinct scents and provide natural defenses. Many Bursera species also store water in swollen trunks, an adaptation that allows them to endure prolonged drought.
Notable Bursera Species
Bursera simaruba, known as Gumbo-Limbo or the “tourist tree,” is widespread from Florida through the Caribbean, Mexico, and Central America. This fast-growing tree has bright reddish-brown bark that peels in thin, papery flakes, resembling sunburned skin. Its semi-evergreen foliage and resilience make it common in tropical dry forests.
Bursera microphylla, called the Elephant Tree, has a swollen, twisted trunk and branches. Found in the southwestern United States and Mexico, this deciduous shrub or small tree has small, light-colored leaves and papery bark that can be rust or golden. Its drought tolerance makes it a distinctive specimen in arid landscapes.
Bursera graveolens, known as Palo Santo or “holy wood,” is native to dry forests in South America, particularly Peru and Ecuador. It is valued for its sweet, woody, and resinous aroma. Its wood and resin have been used in cultural practices for their distinct fragrance.
Cultivating Bursera
Bursera plants thrive in full sun, requiring at least six to eight hours of direct sunlight daily. While they tolerate some partial shade, growth may be slower. Well-draining soil is crucial, as they are susceptible to root rot in overly moist conditions. A sandy or gritty mix, incorporating inorganic materials like pumice or perlite, is ideal for proper drainage, mimicking their natural habitat of rocky or sandy soils with a pH range of 6.0 to 7.5.
These plants are drought-tolerant and prefer infrequent watering. Allow the soil to dry out almost completely between waterings, typically every two to three weeks, and reduce watering during cooler, dormant periods. Bursera plants are sensitive to cold and require warm temperatures, ideally between 70°F and 115°F (21°C and 46°C). They are not frost-tolerant, so protection from freezing temperatures is necessary, with minimal temperatures around 50°F (10°C) being the coldest they should experience. Propagation is from seeds or stem cuttings; cuttings should callous for a few days before planting in a well-draining medium.
Ecological and Cultural Significance of Bursera
Bursera species provide food sources for local wildlife. Birds and mammals consume their fruits, aiding in seed dispersal. Their ability to thrive in harsh, dry environments contributes to the biodiversity and stability of arid and semi-arid landscapes. These resilient plants are suitable for xeriscaping projects.
Bursera plants hold cultural significance through the traditional uses of their resins. The aromatic sap, often called copal, has been used as incense and in traditional medicine by indigenous communities in Mexico and South America. Bursera graveolens (Palo Santo) resins are burned for their sweet, woody scent, believed to cleanse spaces and promote relaxation. Resins are also applied for medicinal purposes, including treating inflammation, pain, respiratory issues, and skin ailments.