Basic Information
Common Name: Bursera
Scientific Name: Bursera
Native Habitat: Primarily arid and semi-arid regions of the Americas, ranging from the southwestern United States down through Mexico, Central America, the Caribbean, and northern South America. They are common components of tropical dry forests, deserts, and scrublands.
History / Discovery / Cultivator
The genus Bursera belongs to the family Burseraceae, which is famous for its aromatic resins, including those that produce frankincense (Boswellia) and myrrh (Commiphora), although these iconic resins come from genera native to Africa and Asia. The genus Bursera itself, however, is uniquely American, with centers of diversity in Mexico.
The scientific classification of Bursera dates back to Carl Linnaeus, who described the genus in 1760. The name Bursera honors Joachim Burser (1583-1639), a German botanist and physician. The plants have been known and utilized by indigenous peoples throughout their range for millennia. Archaeological evidence suggests their use dating back thousands of years.
The importance of Bursera species historically lies significantly in their aromatic resins and wood. Many species produce resins that, when the bark is damaged, flow out and harden. These resins have been traditionally used for various purposes, including incense in religious or ceremonial contexts, as medicinal remedies for ailments ranging from skin infections to digestive issues, and even as adhesives or varnishes. For instance, the resin of Bursera simaruba, commonly known as Gumbo Limbo or Tourist Tree, has been used in traditional medicine to treat burns, fevers, and various other conditions. The wood of many species is also valued for carving or timber, though it is often soft.
Cultivation of Bursera species outside their native range has become increasingly popular, particularly among succulent and caudiciform plant enthusiasts. Species like Bursera microphylla (Elephant Tree), with its thickened trunk-like base and aromatic foliage, are highly prized as ornamental specimens. These plants appeal to collectors due to their unique shapes, drought tolerance, and often fragrant properties. While large-scale commercial cultivation is less common than for agricultural crops, nurseries specializing in xerophytic and succulent plants actively cultivate and propagate various Bursera species to meet the growing demand from collectors and landscapers in suitable climates. The ease of propagation from large cuttings for many species, such as B. simaruba, has also facilitated their spread in cultivation and landscaping in frost-free areas. The history of Bursera, therefore, is a blend of ancient traditional use, scientific classification, and modern horticultural appreciation for these fascinating, resinous inhabitants of the dry Americas.
Plant Care Summary
| Category | General Requirement | Notes |
|---|---|---|
| Light | Full sun to part shade | More sun promotes compact growth; afternoon shade may be beneficial in extremely hot climates. |
| Water | Sparingly | Allow soil to dry out completely between waterings. Highly drought tolerant. Reduce significantly in dormancy. |
| Humidity | Low | Tolerates typical indoor humidity; prefers drier conditions. |
| Temp. Range | Warm | Generally above 50°F (10°C). Most are sensitive to frost. |
| Soil Type | Well-draining | Sandy, gritty, or rocky soil mix. Avoid heavy clay or mixes that retain too much moisture. |
| Fertilizer | Sparingly | Feed lightly once or twice during the active growing season (spring/summer). Use a diluted balanced fertilizer. |
| Toxicity | Mildly irritating | Resins can cause skin irritation in some individuals. Ingestion may cause mild digestive upset. |
Botanical Insights
Adaptations
Bursera species have evolved several fascinating adaptations to thrive in the arid and semi-arid environments they inhabit. One of the most notable is the ability to store water in their trunks and branches, leading to the thickened, often swollen appearance seen in many species, especially those with caudiciform habits like Bursera microphylla. Their bark is often thin and peeling, which is thought to help with thermoregulation by shedding the outer layer and exposing a cooler surface below, or potentially as a defense mechanism against epiphytes and climbing pests. Many species are deciduous, shedding their leaves during the dry season or periods of drought to conserve water, entering a state of dormancy. The production of aromatic resins is another key adaptation; these compounds likely serve as a defense against herbivores and pathogens, making the plants less palatable or sealing wounds effectively.
Propagation Methods
Bursera species can be propagated by both seed and cuttings. Propagation from seed is possible but germination rates can vary and seedlings grow slowly. The most common and often most successful method, particularly for larger species like B. simaruba, is propagation from cuttings. Large, thick stem or branch cuttings can be taken and allowed to callus over for several days or weeks before being placed in a well-draining rooting medium. They root relatively easily when provided with warmth and minimal moisture initially. For species with prominent caudexes, care must be taken during propagation to encourage the desired swollen form.
Toxicology
The primary toxicological concern with Bursera plants relates to their characteristic resins. These resins contain various compounds that can be irritants. Contact with the resin or sap can cause dermatitis or allergic reactions in sensitive individuals, leading to skin redness, itching, or rash. If ingested, the resins can cause mild gastrointestinal upset, such as nausea, vomiting, or diarrhea, due to their irritating properties. While not generally considered highly toxic or deadly to humans or common pets like cats and dogs, it is advisable to prevent ingestion and to handle the sap or damaged parts of the plant with care, especially if you have sensitive skin. The severity of symptoms is typically low, but veterinary or medical attention should be sought if significant amounts are ingested or if severe reactions occur.
Common Problems
Pests:
- Spider mites (especially in dry, indoor conditions)
- Scale insects
- Mealybugs
Diseases:
- Root rot (caused by overwatering and poor drainage)
- Fungal leaf spots (less common, usually related to excessive moisture)
Other:
- Leaf drop (natural response to drought, cold, or dormancy)
- Stunted growth (lack of sufficient sunlight, poor soil drainage, or lack of warmth)
- Soft, mushy stems/caudex (severe overwatering and root rot)
Rarity & Value
Rarity:
The rarity of Bursera species varies greatly. The genus contains numerous species, many of which are common in their native habitats or readily available in the horticultural trade (like B. simaruba). However, some Bursera species are naturally rare due to restricted native ranges, specific ecological requirements, or slow growth rates. Additionally, certain forms or varieties within a species, such as those with particularly attractive caudex shapes or unusual growth patterns, can be harder to find and thus considered rarer by collectors. Difficulties in propagation or specific cultivation needs can also contribute to rarity in the market.
Value:
The market value of a Bursera specimen is influenced by several factors. The species itself is a primary determinant; sought-after species like Bursera microphylla or those with unusual growth habits tend to command higher prices. Size and age are significant – larger, more mature plants, especially those with well-developed caudexes or trunks, are typically more valuable due to their years of growth. The shape and form of the plant, particularly the aesthetic appeal of the caudex or branching structure for collector species, heavily impact value. Current collector trends and demand for specific species also play a role. Plants with good provenance (known origin or reputable grower) or those that are difficult to propagate may also be more valuable.
