Delonix regia is a species of flowering plant in the bean family Fabaceae, subfamily Caesalpinioideae native to Madagascar.

One leaflet is oblong with a length of 4-12 millimetres, it is dark green with a dull upper surface and a paler, greyish bottom.

The compound (doubly pinnate) leaves have a feathery appearance and are a characteristic light, bright green.

[6] Delonix regia is endemic to Madagascar's dry deciduous forests, but has been introduced into tropical and sub-tropical regions worldwide.

[7]: 467  Aside this, it is present in several Southern African countries such as South Africa, Zimbabwe, Malawi, Zambia and Namibia.

It also grows in humid parts of Mexico, especially in the southwest states like Campeche, Chiapas, Oaxaca, Tabasco, Veracruz, and Yucatán.

It can also be found in Belize, The Bahamas, Costa Rica, Cuba, Haiti, Honduras, Nicaragua, the U.S. Virgin Islands, Sint Maarten, Trinidad and Tobago, the Cayman Islands, Grenada,[citation needed] Jamaica, Curaçao, Dominica, Saint Vincent and the Grenadines and Saint Lucia.

[1] Delonix regia is planted in Mediterranean parts of Europe, the Middle East and North Africa, including the southern coast of Spain, the Valencian coast, the Canary Islands, Lebanon, Egypt, Iran,[citation needed] Israel, Jordan, Cyprus and Saudi Arabia.

In Myanmar, where it is called sein pan (စိန်ပန်း), the time of flowering is March in the south and early to late April in the north.

In Malaysia, it is called "Semarak", which used to be the name of a street in the country's capital city, Kuala Lumpur, now renamed as Jalan Sultan Yahya Petra where one of the oldest and highest ranked Malaysian universities, the University of Technology Malaysia's Kuala Lumpur campus is located.

It is very widely grown in Northern Australia, in the southern extremes previously limited to South East Queensland where it is a popular street tree in the suburbs of Brisbane.

In lieu of soaking, the seeds can also be "nicked" or "pinched" (with a small pair of scissors or nail clipper) and planted immediately.

Branches consisting of the current or last season's growth can be cut into 30 cm (12 in) sections and planted in a moist potting mixture.

In the Indian state of Kerala, royal poinciana is called kaalvarippoo (കാൽവരിപ്പൂവ്, kālvarippūv) which means "the flower of Calvary".

There is a popular belief among Saint Thomas Christians of Kerala that when Jesus was crucified, there was a small royal poinciana tree nearby his Cross.

Its blossom is the national flower of St. Kitts and Nevis,[14] and in May 2018 the royal poinciana was adopted by the city of Key West as its official tree.

[15] Known locally as semarak api, Delonix regia is the city flower of Sepang, Selangor, Malaysia.

[17] Hải Phòng is nicknamed Thành phố hoa phượng đỏ ("City of red poinciana").