FLAMBOYÁN: CHARACTERISTICS, HABITAT, REPRODUCTION, USES - BIOLOGY - 2025

The flamboyan or framboyan (Delonix regia) is a large tree with attractive flowers belonging to the Fabaceae family. Known as red acacia, fire tree, sneak, flamboyant, framboyan, malinche, ponciana or tabachín, it is a native species of Madagascar, in southern Africa.

It is a highly valued ornamental plant due to its spectacular flowering of yellow, orange or red tones, and abundant bright green foliage. In this regard, it is a species that has been widely introduced in different tropical and subtropical environments around the world.

Flamboyan (Delonix regia). Source: Scott.zona

The flamboyant tree has a branched trunk with an average height of 8-12 m and a wide parasol crown. Its abundant foliage is made up of compound leaves, bipinnate and with bright green tones, which can be deciduous, perennial or semi-evergreen depending on the environmental conditions.

It is usually used for its excellent shade, as well as for its ornamental character, being during the spring the opportune moment to fully appreciate its incomparable flowering that lasts until the arrival of autumn.

This species has various metabolites that provide multiple medicinal properties. It is also used as food for animals and as firewood for fuel. In fact, in its place of origin it is in danger of extinction due to the loss of its natural habitat and the high demand for its wood to obtain charcoal.

General characteristics

Tree

The flamboyant is a medium to small tree with rounded and wide crowns. It has arched branches, and the crown is more extended than the height of the tree.

It can measure about 60 cm in diameter. They are deciduous trees for short periods, and have pubescent branches, with prominent lenticels.

Fire tree (flamboyán). Nacasma

Leaves

Its leaves are alternate with stipules, uniformly pinnate (bipinnate), and contain 10 to 25 pairs of pinnae. The petiole of the leaves is large, and it has a basal pulvulus, which has 12 to 40 pairs of opposite pinnae.

Reproductive organs

It has elongated inflorescences with multiple flowers, with buds at the tips that protrude from the leaves. The petals have a red margin with a white central part.

The standard petal functions as a signal for pollinators, as it is fully expanded. Then the side margins are shifted inward and the white and yellow colors fade to red. This petal often falls from the flower, ahead of the wing and the keel petals.

It has long, robust pedicels, articulated at each end, ovate bracts, and with conical apices.

This tree has very showy, large flowers, scarlet red or red to orange, which may or may not appear before the leaves. It has a green calyx with 5 lobes on the abaxial surface. While it has a red color with a yellow border on the adaxial surface. In turn, the cup of the chalice is very short.

Collage of Delonix regia flowers. Zodarion73

For its part, the androecium has ten serrated stamens, and all of them are fertile. The filaments are of uneven length, with a curved, pubescent adaxial base, with yellow and red anthers.

The carpel is inserted in the center of the small nectiferous receptacle. It has an elongated and pubescent ovary with a style equal to or protruding from the stamens. It has a pointed stigma and numerous ovules.

The gynoecium, like that of practically all Caesalpinioideae, consists of a single carpel that is often very similar in different tribes and genera. However, the diversity of the type of fruits of this family is remarkable.

Fruit

Its pendulum-shaped fruits are septate and elongated. Sometimes they measure up to more than 0.6 m, with a long stay in the tree; they eventually open along your sutures.

Probably the term legume comes from the definition of the fruit of the members of leguminous plants. It is usually defined as a dry single-skinned fruit that occurs along both sutures.

View of the flamboyant fruits. Jorge Chamber

Seeds

It presents numerous seeds, located in transverse depressions of the pod valves, with an ellipsoidal shape, thick, red-brown in color, with an elongated and laterally thickened embryo, and with an endosperm present.

Just as there are different types of fruits, there are also different dispersal mechanisms for them. In this sense, the dehiscent fruits of the flamboyant are dispersed by the wind, or mechanically when they fall to the ground.

Phytochemistry

Lupeol, which is a triterpenoid active principle, and the phytosterol β-sitosterol have been identified in the trunk and bark of Delonix regia. In addition, in flowers and seeds it contains the flavonoids cyanidin, kaempferol, quercetin, 3-0-β-genobioside and 3-0-β-glucoside.

Taxonomy

- Kingdom: Plantae.

- Division: Magnoliophyta.

- Class: Magnoliopsida.

- Subclass: Rosidae.

- Order: Fabales.

- Family: Fabaceae.

- Subfamily: Caesalpinioideae.

- Tribe: Caesalpinieae.

- Gender: Delonix.

- Species: Delonix regia (Bojer ex Hook.) Raf.

Etymology

- Delonix: generic name, which is derived from the Greek terms δηλος (delos), which means "evident", and ονυξ (onyx), which means "claw", referring to the shape of the petals.

- regia: Latin adjective that means "royal or royal".

Synonymy

- Poinciana regia Bojer.

- Poinciana regia Hook.

Habitat and distribution

Delonix regia is native to the dry deciduous forest of Madagascar. However, it has been introduced and naturalized in various ecosystems around the world. This species requires a tropical or subtropical climate to grow and develop effectively, being tolerant to drought and salty soil conditions.

Sinuous trunk of the flamboyant. Source: Forest & Kim Starr

In America its cultivation is widely extended, from the southern United States, Hawaii, the Virgin Islands, Puerto Rico and the Caribbean. As well as in Central America, Colombia, Venezuela, Ecuador, Bolivia and Peru, to Paraguay, Brazil and subtropical forests to the north of Argentina.

The flamboyant has been naturalized in various regions of Australia, India, South Africa, the Canary Islands and Madeira. Some varieties have been established on the Iberian Peninsula, on the coasts of Valencia and Alicante, and in the city of Cádiz.

Reproduction

The flamboyant reproduces sexually through seeds, and asexually through cuttings and air layers. On some occasions the grafting of varieties of different colors is common to highlight the commercial value of the species.

Propagation by seeds

Viable seeds are obtained from healthy, vigorous, pest and disease-free plants with high seed production. Harvesting is done directly from the plant, from pods that have been attached to the tree for more than a year.

The seeds require a pre-germination treatment consisting of scarification, followed by imbibition of the seed for 24 hours at room temperature. Sowing is done in seedlings, germinators or polyethylene bags, placing one seed per point at a depth of 1-2 cm.

For sowing it is recommended to use as a substrate a mixture of 30% black peat and perlite plus 10% organic fertilizer. After sowing, abundant irrigation is applied, keeping the substrate permanently moist.

Since the establishment of the plantation, it is kept under free solar radiation and constant humidity without getting to flood. In this way, after 5-7 days, the germination of the new seedlings begins.

Fruits of flamboyant. Source: Atamari

Propagation by cuttings

Propagation by cuttings or cuttings is a vegetative multiplication technique that allows obtaining productive plants in the shortest possible time. The best time to do this type of propagation is during the fall.

Cuttings 40-50 cm long are selected from sturdy, semi-woody branches 1-2 cm in diameter. The cut is made in a bevel, trying to cover the region of the cut on the plant with healing paste.

The cutting is impregnated with phytohormones and introduced into a porous substrate composed of a mixture of black peat, perlite or coconut fiber. The cuttings are located in a shady place, with continuous humidity to favor the sprouting of leaf buds.

Propagation by air layering

Layers are preferably carried out in early spring in order to take advantage of the cool conditions for rooting the tissues. With the help of a clean and disinfected razor, the bark of a terminal branch 2-3 cm in diameter is sanded.

The cutting is moistened with rooting hormones and covered with plant material such as coconut fiber or cane. Subsequently, it is wrapped with a black plastic bag, trying to firmly tighten the ends with a string.

A syringe is used to wet the substrate continuously, according to the environmental conditions it can be done every 2-3 days. After 30 days, the layer area begins the proliferation of adventitious roots. At 60 days, the layer will be ready to transplant.

In this case, the tie is loosened and the new adventitious roots are cut flush. The seedling thus obtained is sown in polyethylene bags or plastic pots and they are kept under similar growing conditions as if it were a cutting.

Grafts

The grafting technique is used in gardening to achieve more showy plants at a commercial level. The semi-woody tissues of the flamboyant are adapted to the grafting technique, being the cleft grafting technique the most appropriate.

In this regard, a deep cross section is made on the rootstock that is at least 1-2 cm thick. Subsequently, a slit is made in the middle with the help of a clean and disinfected razor.

The part to be grafted is a stem fragment with 2-3 buds of the plant to be propagated. A spike-shaped cut is made on the graft that is inserted into the groove of the pattern, ensuring the union of the conductive tissues.

The graft thus made is covered with adhesive graft tape and kept under semi-shade until the union of both tissues is completed.

Applications

Ornamental

One of the main uses of flamboyant in warm climates is as an ornamental plant in avenues and public spaces. In fact, it is used as a shade tree due to its wide foliage, associated with the attractive colors during the flowering season.

Planting is common on the edges of roads, streets, avenues and highways, as well as in squares, parks and open fields. It is also common to find it in houses, farms and estates, embellishing patios and gardens; some gardeners use it to make bonsai.

Ornamental use in parks. Source: I, Avi1111

Nutritional supplement

In some regions, the branches and pods of the flamboyant are used as food for cattle due to their high protein content. The flowers are used as a nutritional supplement for poultry in order to improve the hardness of the eggshell.

Traditional

In some communities in the Caribbean and South America, the seeds are used to make decorative elements such as bracelets, necklaces or other accessories. In the Antilles, the pods with their dried seeds are used as a musical instrument called shak-shak, similar to the traditional maracas.

Medicinal properties

Structures like leaves, flowers, and bark contain active compounds. However, the leaves are the richest source of these components. The flamboyant plant has been reported to have uses or properties such as antibacterial, antidiabetic, antidiarrheal, antifungal, anti-inflammatory, antimalarial, antimicrobial, antioxidant, cardioprotective, gastroprotective, hepatoprotective.

Also, it is used in traditional medicine to treat disorders such as rheumatoid arthritis, diabetes, pneumonia, and malaria.

As for its chemical compounds, flavonoids, alkaloids, saponins, sterols, tannins, carotenoids, and phenolic acids are included. Of these, flavonoids and triterpenes are reported as pain relievers, and flavonoids also have high antioxidant power. The bark is known to have emetic properties, as its aqueous extract induces vomiting.

The fraction rich in metabolites, a product of flower and seed extracts, has antifungal activity against Aspergillus niger, Aspergillus flavus, Rhizopus bataticola, and Fusarium oxysporum.

Within its medicinal uses, it is known that the leaves of Delonix regia are used in the traditional medicine of Bangladesh for the treatment of diabetes, without this having been supported by scientific studies that can support the effect of this tree.

For its part, the leaves, after cooking, have antirheumatic effects. The methanolic extracts of the leaves have shown significant analgesic activity. Whereas, the ethanolic extracts of the leaves have shown cardioprotective activity, which is possibly due to the vasodilation and anti-inflammatory activity they produce. The oil obtained from the leaves produces an antifungal effect.

To this end, several studies have been carried out, one of which stands out to evaluate the possible decrease in glucose tolerance with methanolic extracts from the leaves of this plant species. When using mice with induced hyperglycemia, it turns out that these extracts can reduce a high level of glucose in the blood.

Care

The Delonix regia plant adapts to soils with a loamy-clay texture, since its extensive root system develops vigorously under these conditions. Likewise, it performs well in soils with a wide pH range, from neutral to slightly acidic or alkaline conditions.

The implantation of the crop -seed or cutting- is carried out on a fertile substrate containing black peat, perlite and worm humus (10%). During the first years, the plant is kept in a pot or polyethylene bags, and the transplant is carried out to the final site after 2-3 years.

Foliar area of ​​the flamboyant. Source: Alejandro Bayer Tamayo from Armenia, Colombia

Established field cultivation, weeding around the plant is recommended in order to avoid competition for space and humidity. Irrigation is carried out on a regular basis, trying to keep the soil humidity constant, since it supports drought but does not tolerate humidity saturation.

In summer it is recommended to apply irrigations every 2-3 days as long as the temperatures are above 30º C. During the cool months, the irrigations can be applied 1-2 times a week.

Regarding the arrangement, the flamboyant requires full sun exposure, and shady or semi-shaded conditions negatively influence its flowering. This species does not require frequent pruning, it also tolerates strong winds.

The ideal temperature for its cultivation is between 10-35º C. It is very sensitive to cold, so it does not survive frosts below -4º C.

Fertilization and manuring practices are carried out in early spring and during summer. It is advisable to apply a fast-acting fertilizer or compost-based organic fertilizers. During the fall and winter, the fertilizer dose is reduced by half once a month.

Plagues and diseases

The Delonix regia is a robust species resistant to attack by pests and diseases. However, it can be attacked by mealybugs, aphids, termites, ants, and adverse environmental conditions, such as extreme temperatures and high rainfall.

Pest control is carried out with controlled applications of insecticides based on pyrethrins or abamectin. In high humidity conditions, the plant can be affected by the Phytophthora fungus, which can be controlled with a broad spectrum fungicide.

References

1. Delonix regia (2019) Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
2. Delonix regia (2014) Virtual catalog of flora of the Aburrá Valley by UEIA. Recovered at: catalogofloravalleaburra.eia.edu.co
3. Delonix regia (Bojer) Raf. (2018) SIRE-Technological Packages. National Forestry Commission CONAFOR - CONABIO
4. Duno de Stefano, Rodrigo (2012) The flamboyant (Delonix regia) an ambassador of Madagascar to the world. CICY Herbarium, Natural Resources Unit. Yucatan Scientific Research Center, AC (CICY). Mexico.
5. Flamboyan (2017) Trees and shrubs: Gardening On. Recovered in: jardineriaon.com
6. Gilman, Edward F. & Watson, Dennis G. (1993) Delonix regia Royal Poinciana. Forest Service. Department of Agriculture.
7. Martínez Ramírez, S. (1996). The germination of Seeds of Delonix regia (Framboyan): is promoted with boiling water and inhibited with Gibberellic Acid. Oaxaca. MX.
8. Modi, A., Mishra, V., Bhatt, A., Jain, A., Mansoori, MH, Gurnany, E., & Kumar, V. (2016). Delonix regia: historic perspectives and modern phytochemical and pharmacological researches. Chinese journal of natural medicines, 14 (1), 31-39.
9. Rivera Ocasio, Dania (2011) Flamboyán - Delonix regia. Agricultural Extension Service. College of Agricultural Sciences, University of Puerto Rico.