Jerusalem thorn, West Indian prickly broom, jelly bean tree, horsebean, Barbados flowerfence (Eng); palo verde, parkinsonia, espino de Jerusalén, cina-cina (Spa); espinheiro-de-Jerusalém, cina-cina (Por).
DID YOU KNOW...? Incisions are made in the trunk of the Jerusalem thorn to extract a rubber similar to gum arabic that is used, among other things, for sticking stamps and making sweets.
This is a small, thorny tree about 3-7 m tall, with green bark, a parasol-shaped crown and hanging foliage. New twigs are flexible, pendulous and grow in a zigzag form. The leaves are alternate, compound, and twice pinnate, although they do not seem to be. In fact, the leaf comprises a short principal rachis that has become a spine, from which arise 2-4 pinnae, or sometimes more, that are 20-30 cm in length, and which have numerous small leaflets. These are linear or narrowly obovate, greyish green in colour, with an entire margin, and spatially separated. In the Canary Islands it is considered to be an evergreen tree, although the small leaflets drop very frequently to the ground, giving it a reputation for being a ‘dirty tree’. It has very striking blooms, with hanging clusters comprising numerous, fragrant, bright yellow flowers spotted with purple or reddish marks. The narrow, elongated fruit are legumes (a little more than 10 cm long) that pinch in between the seeds. Most of these pods contain only one or two seeds, although they can have as many as 8. The seeds are elongated and very hard. They are shiny green with brown or purple mottling and are edible, with a pleasant flavour.
The Jerusalem thorn prefers a warm climate and is fairly tolerant of the salty influence of the sea, drought, strong winds, and temporary flooding, as well as a wide range of soil types. This tree is also able to adapt to high temperatures, as it can drop its leaves to decrease transpiration and photosynthesise through its green parts. It is mainly found in landscaped areas and along the sides of roads. The first record of its cultivation in the Canary Islands is from 1879, in the Jardín de Aclimatación de La Orotava botanical garden, where still today it is used as an ornamental. It sometimes escapes from cultivation, and individual specimens become naturalised on urban plots of land, in roadside ditches and, more rarely, on slopes and in ravines. It is particularly associated with urban areas near the coast, where it forms dense thickets.
This species is native to tropical America, where it lives from Mexico to the north of Argentina and Uruguay. The Jerusalem thorn has been cultivated in the Canaries since 1879. Currently, it is only found established in the wild, and so far only to a limited extent, in Tenerife and Fuerteventura. It is included in the Atlas of invasive alien plants of Spain.