The Royal Poinciana or Flamboyant Tree, Delonix regia (family Fabaceae), has been described as the most colourful tree in the world. While it might be difficult to validate this claim objectively, it is easy to see why it is plausible. The tree's vivid red/orange flowers and bright green foliage make it an exceptionally striking sight. It is sometimes known as the Peacock Flower, Flame of the Forest or Flame Tree, but since this last name is also used for a number of other unrelated trees, its use is not recommended.

The Royal Poinciana is native to Madagascar, where it is found in the West Malagasy forest. In the wild it is endangered, but it is widely cultivated elsewhere. In addition to its ornamental value, it is also a useful shade tree in tropical conditions, because it usually grows to a modest height (typically around 5 m, though it can reach as high as 12 m) but spreads widely, and its dense foliage provides full shade. In countries with a marked dry season, it sheds its leaves during the drought, but in other areas it is virtually evergreen.

The flowers 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. The naturally occurring variety flavida has yellow flowers. Seed pods are dark brown and can be up to 60 cm long and 5 cm wide; the individual seeds, however, are small, weighing around 0.4 g on average. The compound leaves have a feathery appearance and are a characteristic light, bright green. They are doubly pinnate: Each leaf is 30-50 cm long and has 20 to 40 pairs of primary leaflets or pinnae on it, and each of these is further divided into 10-20 pairs of secondary leaflets or pinnules.

Traders shading under Royal Poincianas outside the church of Santo Domingo, Oaxaca, Mexico

The Royal Poinciana requires tropical or near-tropical conditions, and in the United States is found only in Florida and Hawai'i. However it can tolerate drought, and also salty conditions; it is very widely grown in the Caribbean. It is regarded as naturalised in many of the locations where it is grown, and is seen as an invasive species in Australia, partly because its dense shade and root system prevent the growth of other species under it. This species is also found in India and is referred to as the Gulmohar.

Reference

• Floridata data base (http://www.floridata.com/ref/d/delo_reg.cfm)