Delonix regia

In the continental United States, it grows in South Florida, Central Florida,[4] and in the Rio Grande Valley of South Texas. It also grows in humid parts of Mexico, especially in the Yucatan peninsula.

In the Caribbean it is featured in many Dominican and Puerto Rican paintings. It can also be found in Belize, The Bahamas, Costa Rica, Cuba, Haiti, Dominican Republic, Honduras, Nicaragua, U.S. Virgin Islands, Sint Maarten, Trinidad and Tobago, Cayman Islands, Grenada, Jamaica, Curaçao, Dominica and Saint Vincent And The Grenadines and Saint Lucia. It is the national flower of St. Kitts and Nevis. It can also be found in Bermuda, and Hawaii. The town of Peñuelas, Puerto Rico, located about 12 miles or 19 kilometers west of Ponce, is nicknamed El Valle de los Flamboyanes ("The Valley of the Poinciana Trees"), as many flamboyant trees are found along the surrounding Río Guayanes, Río Macana, and Río Tallaboa rivers.

It grows in Paraguay and Brazil.[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, Israel, Jordan, Cyprus and Saudi Arabia.

The tree is planted in India, where it is referred to as the May-flower tree, Gulmohar or Gul Mohr.[5] In West Bengal, and Odisha it is called Krishna Chura (কৃষ্ণচূড়া/କୃଷ୍ଣଚୂଡ଼ା). In Sri Lanka it is known in Sinhala as the Maara tree, although for a short while it was known as the Lamaasuriya tree after Le Mesurier, the British civil servant who was responsible for introducing it as a shade tree.[6] It is also grown in Karachi, Pakistan. In Mauritius and La Réunion it announces the coming of the new year.

In Bangladesh it is known as krisnachura(কৃষ্ণচূড়া). You can find this tree in various places in Bangladesh. It is found all over Dhaka City and is one of the iconic symbols of the Bengali month of Boishakh. In Nepal it is known as Shirish.

In Myanmar, where it is called Sein-pann-ni, the time of flowering is March in the south and early to late April in the north. It is planted in gardens and as a roadside tree. In Myanmar, this tree is a sign of the Thingyan Festival (13–16/17 April). In the Philippines, its flowering signals the imminent arrival of the monsoon rains. It also grows in Thailand and Indonesia. In Vietnam it is called "phoenix flower" and mostly grows in Haiphong. 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. "Semarak Api" is also the official flower of the Sepang district.

It grows in Southern China such as in Hong Kong. It is the official tree in Tainan, Taiwan; Xiamen, Fujian Province, and Shantou, Guangdong Province, People's Republic of China. National Cheng Kung University, a university located in Tainan, included royal poinciana on its emblem.

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. It now grows and blooms successfully in Sydney and other parts of New South Wales.

It grows in Guam, and is the official tree of the Commonwealth of the Northern Mariana Islands.

It is widely grown in Southern Nigeria and are quite common in Southern African countries, like South Africa and Namibia.

The royal poinciana requires a tropical or near-tropical climate, but can tolerate drought and salty conditions. It prefers an open, free-draining sandy or loamy soil enriched with organic matter. The tree does not like heavy or clay soils and flowers more profusely when kept slightly dry.

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 pair of 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 (12 in) 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 (12 in) 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.

In addition to its ornamental value, it is a useful shade tree in tropical conditions, because it usually grows to a modest height (mostly 5 m or 15 ft, but it can reach a maximum height of 12 m or 40 ft) but spreads widely, and its dense foliage provides full shade. In areas with a marked dry season, it sheds its leaves during the drought, but in other areas it is virtually evergreen.