Mexican poinciana is found in Texas only in the extreme lower Rio Grande Valley. It is grown mainly for its highly fragrant, golden flowers borne in attractive racemes 3 to 6 inches long. In tropical regions it can grow to a tree of 15 feet, but north of its native range it usually performs as an herbaceous perennial, growing to a 3 to 6 foot shrub in a growing season. It is highly ornamental with its spectacular flowers and ferny foliage, and thrives in heat, tolerating reflected heat that many flowering shrubs and trees cannot.
Erythrostemon mexicanus is a species of flowering plant in the pea family, Fabaceae. Common names include Mexican holdback, Mexican caesalpinia, and tabachín del monte. It is native to the extreme lower Rio Grande Valley of Texas in the United States and south to central Mexico. Its range in Mexico includes the northeast and further south along the Gulf coast as well as the Pacific coast in Nayarit, Jalisco, Colima, and a small portion of Sinaloa.
Mexican holdback is a small evergreen tree or large shrub, reaching a height of 3–4.6 m (9.8–15.1 ft) and a spread of 1.8–3 m (5.9–9.8 ft). Leaves are bipinnately-compound and dark green.Each leaf has five to nine pinnae 4–9 cm (1.6–3.5 in) in length. Pinnae are composed of four to five leaflets that are 1–2.5 cm (0.39–0.98 in) long and 0.7–1.3 cm (0.28–0.51 in) wide.Yellow, slightly fragrant flowers are produced on 7.6–15.2 cm (3.0–6.0 in) terminal spikes of 10 to 30.Blooming takes place from February to July, often continuing to October. The fruit is a dehiscent tan or yellow seedpod 5.1–7.6 cm (2.0–3.0 in) in length.