Common name: West Indian lilac

Originating in the Eastern Caribbean and northern parts of South America, this small flowering tree is typically 5 to 10 m (16 to 32 ft) tall, occasionally reaching up to 15 m (50 ft).

It usually develops a short, slender trunk with smooth, grey or pale brown bark and a sparingly branched wide-spreading crown of long wispy branches arching downwards.

The leaves are long and feathery, with up to forty medium green, oblong leaflets arranged in pairs along the length. They droop from the arching branches, accentuating the plant's weeping appearance, and either remain on the tree throughout the year or fall, where the dry season is long and pronounced.

Flowering is at the start of the rainy season, coinciding with spring in its native range or is on-and-off in regularly watered gardens and landscapes.

The flowers are purple, sweetly fragrant and bloom on erect spikes above the foliage, though the flowering period is short. Lance-shaped seedpods soon follow and are green at first but turn light brown when mature and persist on the tree for a long time.

Use

It is mainly cultivated as a shrub or small tree, particularly in gardens in its native region, where its showy foliage and flowers are much admired. 

The leaves are reported to contain high concentrations of the poison Rotenone, a commonly used organic insecticide. They have a history of use by native people as a fish poison and are a potential source of compounds for the manufacture of Biopesticides. 

There are references in various publications to the use of the bark in Maya culture for brewing an intoxicating, alcoholic beverage known as 'Balché'.

Climate

Grows naturally in moderately humid tropical lowland climates, generally frost-free areas with annual lows of 19 to 25°C annual highs of 28 to 35°C, annual rainfall of 800 to 1700 mm and a dry season of 3 to 7 months.

Growing

New plants are usually grown from seed, which the tree does not normally produce a lot of. Being leguminous, it fixes its own nitrogen, which allows it to grow on nutrient-poor soils. It is often found on dry limestone hillsides in its native range, suggesting good tolerance to drought and alkaline soils.

Problem features

All parts of the plant are poisonous, and as a precaution, honey produced by bees foraging the flowers should not be consumed. There are reports of domestic animals being poisoned after consuming the seed.

It is reported to have naturalised in Florida. Still, there does not appear to be any records of it being a serious weed anywhere in the world.

Books

• Allen, O. N. & Allen, E. K. 1981, The Leguminosae : a source book of characteristics, uses, and nodulation, University of Wisconsin Press, Madison, Wisconsin

• Barwick, M., et al. 2004, Tropical & subtropical trees : a worldwide encyclopaedic guide, Thames and Hudson, London

• Mathias, M. E., 1982, Flowering plants in the landscape, University of California Press, Berkeley

• Singh, D. ed., 2014. Advances in plant biopesticides, Springer Publishing, New Delhi, India

• Sterling, D. 2014, Yucatán : recipes from a culinary expedition, First edition, Austin, TX University of Texas Press