Tipuana tipu

Tipuana tipu is native to subtropical climates in South America. It forms a medium-sized tree with a wide and spreading crown, as wide as it is tall, appreciated for the shade it creates. The flowering that lasts all summer is composed of pretty yellow to orange flowers, with a small red spot in the centre. Practically maintenance-free and capable of adapting to most soils, from acidic to limestone, as long as they are well-drained. Tipuana grows in full sun. It appreciates watering but will tolerate drought once well-rooted.

This tree, known as Palo rosa in Argentina (pink wood, due to its reddish sap), belongs to the large Fabaceae family. Tipuana genus has only one species, native to South America, which grows in arid or semi-arid high-altitude climates (northern Argentina, Brazil, and Bolivia). Depending on the climate, it forms a medium to large tree, with heights ranging from 15 to 40m (49 to 131ft), growing faster with access to water. Evergreen in mild winter climates, it can become deciduous if subjected to a period of winter cold. A well-established tree can withstand frost down to -5°C (23°F), or even -7°C (19.4°F), provided the soil is well-drained, as stagnant moisture intensifies the cold effect.

The trunk, with its fissured reddish-brown bark, supports a widely spreading irregular crown. The branches are adorned with fairly light green compound odd-pinnate leaves, consisting of 15 to 21 elliptical leaflets. Approximately 25cm (10in) long, the leaves are numerous, forming a dense and abundant mass of vegetation. The flowering blossoms in summer, from June to August, presenting butterfly-shaped flowers. They are grouped in trailing axillary or terminal panicles, measuring 2 to 4cm (1 to 2in) in diameter, and bloom throughout summer. They are composed of 5 unequal and independent petals, with the largest one called the standard. Their yellow-orange colour is enhanced by a central red spot on the standard, creating a pleasing contrast. This bright summer flowering stands out well against the foliage mass, which is why this tree is used as an ornamental species in urban areas in South America. These aesthetically pleasing flowers are also attractive to bees and pollinating insects. Interestingly, it does not produce pods like the majority of species, but the flowers develop into samaras, similar in appearance to those of maple trees. Initially green and measuring 3 to 7cm (1 to 3in) in length, they turn brown when mature before being dispersed by the wind, either at the same time or after the leaves have fallen.

In South America, it provides timber for construction, while the abundant foliage is used as fodder for animals.

Hardy down to -5°C (23°F), and even able to withstand brief frosts down to -7°C (19.4°F). In our climates, it does not reach the same proportions as in its native regions, generally forming a medium-sized tree, 10m (33ft) or less, with a crown usually as wide as its height. Highly adaptable, it grows best when provided with summer watering, but it also withstands drought once established. It can thrive in acidic, neutral, or even slightly alkaline soils, and also tolerates slightly salty terrain. Its only requirement is to be planted in well-drained soil and in a location not too exposed to the wind.

Tipuana tipu will be perfect in mass plantings or as a standalone specimen, taking care to maintain a safe distance from buildings due to its powerful root system. Its exotic appearance will complement other distinctive plants, such as Callistemon viminalis 'Hot Pink', a bottlebrush that forms beautiful spikes of fuchsia pink flowers. Alyogyne huegelii is also one of those flowers with its astonishing blue-mauve colour that evokes distant lands. Cestrum purpureum, an attractive shrub with tubular red-purple flowers, will also be a good companion to complete this tropical scene.