Delonix regia is a species of flowering plant in the bean family Fabaceae, subfamily Caesalpinioideae. It is noted for its fern-like leaves and flamboyant display of flowers. In many tropical parts of the world it is grown as an ornamental tree and in English it is given the name royal poinciana or flamboyant. It is also one of several trees known as Flame tree.
This species was previously placed in the genus Poinciana, named for Phillippe de Longvilliers de Poincy, the 17th century governor of Saint Christophe (Saint Kitts). It is a non nodulating legume.
The flowers of Delonix regia are large, with four spreading scarlet or orange-red petals up to 8 cm long, and a fifth upright petal called the standard, which is slightly larger and spotted with yellow and white. They appear in corymbs along and at the ends of branches. The naturally occurring variety flavida (Bengali: Radhachura) has yellow flowers. The pods are green and flaccid when young and turn dark-brown and woody. They can be up to 60 cm long and 5 cm wide. The seeds are small, weighing around 0.4 g on average. The compound leaves have a feathery appearance and are a characteristic light, bright green and are doubly pinnate. Each leaf is 30–50 cm long with 20 to 40 pairs of primary leaflets or pinnae, each divided into 10–20 pairs of secondary leaflets or pinnules.
The royal poinciana is most commonly propagated by seeds. Seeds are collected, soaked in warm water for at least 24 hours, and planted in warm, moist soil in a semi-shaded, sheltered position. In lieu of soaking, the seeds can also be 'nicked' or 'pinched' (with a small scissors or nail clipper) and planted immediately. These two methods allow moisture to penetrate the tough outer casing, stimulating germination. The seedlings grow rapidly and can reach 30 cm in a few weeks under ideal conditions.
Less common, but just as effective, is propagation by semi-hardwood cuttings. Branches consisting of the current or last season's growth can be cut into 30 cm sections and planted in a moist potting mixture. This method is slower than seed propagation (cuttings take a few months to root) but is the preferred method for ensuring new trees are true to form. As such, cuttings are a particularly common method of propagation for the rarer yellow-flowering variety of the tree.