Delonix regia is a fast-growing tree with an umbrella shaped, spreading crown with the long, nearly horizontal branches forming a diameter that is wider than the tree’s height.
Usually evergreen, the trees are deciduous in areas where the dry season is long and pronounced.
The tree grows 10 - 18 metres tall, with a large, buttressed bole that can attain a girth of up to 2 metres.
A multipurpose tree, it is harvested from the wild for a wide range of local uses, including for medicines, food, timber, fuel and beads. It is cultivated as a shade tree in plantations and is used to stabilize and enrich the soil. This species is one of the most widely cultivated ornamental plants in the world, being grown as an ornamental in gardens and by the sides of roads throughout the tropics.
Flame tree has become almost extinct in its native range of Madagascar.
The main native subpopulations are found in areas that are threatened from charcoal production.
The tree is classified as 'Vulnerable' in the IUCN Red List of Threatened Species (2010).

Known Hazards

None known

Habitat

Forests in warm humid areas at elevations from sea level up to about 1,000 metres.

Cultivation Status

Cultivated, Ornamental, Wild

Cultivation Details

A plant of low to medium elevations in the moist tropics, being found at elevations from sea level to 2,000 metres.
It grows in areas where the mean annual temperature ranges from 14 - 26°c, and the mean annual rainfall is over 700 mm.
It can succeed in areas with both high and scanty rainfall.
Trees can grow at higher altitudes than recommended, but flowering becomes erratic.
The tree demands light and grows weakly and sparsely under shade
The species seems to tolerate many types of soils from clay to sandy, but it prefers sandy soils.
Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 7.5.
Established plants are very drought tolerant.
The trees have shallow root systems and the wood is weak; they are therefore liable to being uprooted during strong storms and broken by strong winds, and so are best planted in sheltered positions.
There are some concerns that the plant might become invasive in some of the areas where it is cultivated.
Trees starts flowering in their 4th or 5th years.
In moist places, the tree begins to develop young foliage before the flowering season and does not flower prolifically. It also flowers less prolifically on the shady sites than on the sunny sites.
Planting of trees on dry sites therefore promotes copious flowering.
In regions with heavy rainfall, every tree seems to follow its own rhythm of shedding of leaves and flowering.
The tree has a superficial, shallow rooting system, and competes successfully with the neighbouring shrubs and flowering plants, rendering bare the ground under its canopy.It should therefore be planted away from other plants in the gardens.
The surface root system can become a problem, sometimes breaking sidewalks and walls.
Natural regeneration is common.
Young plants are not fire resistant and should be protected from grazing.
A fast-growing tree, it responds well to pollarding.
Careful pruning will achieve good crown form.

Edible Uses

Seedpod.
The seedpods are up to 50 cm long, 6cm wide, and 5mm thick.

Although we have seen no reports that the mature seeds of this plant are eaten, research has shown that they are a potential nutritious food for humans. They contain around 48% carbohydrate, 8.7% protein and 17.2% fats, plus a good range of minerals, though rather high in sodium. Antinutritional compounds such as tannins, saponins and oxalates are present, but in lower concentrations than in many commonly eaten foods. The sodium to potassium ratio is rather high and could lead to heart problems in later life if the seed becomes a major part of the diet - though eating the seeds with foods rich in potassium and low in sodium would restore a balance.
The seed contains around 17.2% of a sweet-smelling, amber-coloured oil. The oil is rich in linoleic acid (37.1%), plus palmitic acid (23.9%), stearic acid 8.2%), linolenic acid (7.6%), oleic acid (4.9%), and ricinoleic acid (4.5%)
A gum obtained from the tree is used in the food industry.

Medicinal

The leaves, flowers, seed and bark of this plant contain a range of medicinally active compounds, though the leaves are generally the richest source of most of these compounds.
The plant is reported to have antibacterial, antidiabetic, antidiarrhoeal, antifungal, antiinflammatory, antimalarial, antimicrobial, antioxidant, cardio-protective, gastro-protective, hepato-protective and wound healing activity. It is used in folk medicine to treat a range of disorders, including constipation, inflammation, rheumatoid arthritis, diabetes, pneumonia, and malaria.
The active compounds include flavonoids, alkaloids, saponins, sterols, beta-sitosterol, lupeol, tannins, carotenoids, and phenolic acids.
Flavonoids and triterpenes have been shown to have analgesic activities and the flavonoids are also powerful antioxidants.
The bark has medicinal properties.
An aqueous extract has shown emetic properties.
An aqueous extract of the flowers is active against roundworm.
The metabolite-rich fractions of the sequentially extracted flowers and seeds have shown antifungal activity against Aspergillus niger, Aspergillus flavus, Rhizopus bataticola and Fusarium auxisporum.
A leaf decoction presumably has anti-rheumatic effects.
In eastern Nigeria the leaves are used traditionally for treating pain.
The leaves contain flavonoids, phenolic compounds, triterpenes and sterols. A methanolic extract of the leaves has shown a significant analgesic potential
An ethanol extraction of the leaves has been shown to exert a cardio-protective effect, at least partly due to its vasodilatory and antiinflammatory activity. It has also shown potential for improving liver and kidney functions whilst showing no negative side effects.
An essential oil obtained from the leaves has shown fungicidal properties.

Agroforestry Uses

The tree is planted to provide shade in tea plantations, compounds etc.
The tree can be planted as live fence posts.
It is grown on eroded sites for erosion control, and for soil rehabilitation and improvement through atmospheric nitrogen fixation.

Other Uses

The tree yields a thick mucilage of gum, produced in yellowish or reddish-brown warty tears.
The gum is soluble in water, forming a thick opalescent mucilage. It contains a large quantity of calcium oxalate.
The seeds contain gum that may find use in the textile and food industries.
The seeds contain around 17.2% oil. This oil contains normal glycerides, low unsaturation and will be very good for the production of soaps and shampoos.
The hard, elongated seeds are occasionally used as beads and to make necklaces.
The aqueous extracts of the plant contain allelopathic compounds, including phenolic acids, alkaloids and flavonoids; these can be used as natural herbicides and pesticides to increase the productivity of agricultural crops.
An essential oil obtained from the leaves is fungicidal.
The heartwood is yellowish to light brown; the sapwood light yellow.
The wood is soft, heavy, coarse grained, weak, brittle, takes a good polish and is rather resistant to moisture and insects although very susceptible to attack by dry-wood termites.
A very durable construction timber, but large dimension wood is rarely available.
The large pods as well as the wood are used for fuel
The wood is made into charcoal.

Propagation

Seed - has a hard, woody testa and takes a long time to germinate. It may lie for 2 - 3 years in the soil without germinating and usually take 12 - 349 days to germinate.
To break this dormancy the seed needs to be scarified by carefully abrading a small part of the seed coat, being careful not to damage the embryo.
Alternatively, pour a small quantity of almost boiling water over the seed, making sure it cools down before the seed is cooked, then soak the seed for 12 - 24 hours in warm water prior to sowing. After treated seeds are sown in unshaded nursery beds, they germinate within 5 - 10 days, with a germination rate of up to 90%.
Subsequent growth in the nursery is quite fast.
Seedlings watered and weeded regularly are planted out in the rainy season, with a total time required in the nursery being 3 - 5 months.
Keeping the plants for more than 9 months is not desirable, as they become too tall to handle, but seedlings can be transplanted even when 20 - 25 cm tall.
Seeds can be stored for a long time if insect attack is avoided, which can be done by adding ash to the seeds.
Seed storage behaviour is orthodox and a germination rate of 47% has been recorded after 9 years of storage at room temperature; with no loss in viability following 4 years of storage.
Trees can also be propagated from branch cuttings.