Jacaranda

Overview

Jacaranda is a plant that originates from central and eastern South America, including Uruguay, some parts of Argentina (Entre Rios, Jujuy, Salta, Tucuman), Paraguay (Alto Paraguay, Cordillera), to Bolivia, Brazil. It has been introduced as an ornamental plant in many tropical regions of South America, because this plant has the beauty of its flowers. Apart from being beautiful, Jacaranda flowers also have many other benefits, including providing shade and an effective windbreak plant, a source of material for making poles as well as small items such as tool handles and carvings, an excellent source of nectar for Africanized honey bees in Ethiopia. Traditionally J. mimosifolia also has benefits as a medicinal plant. It is believed that the community is able to overcome various disease complaints. In the IUCN Red List of Threatened Species (2011), Jakaranda has been classified as a 'Vulnerable' plant.

Vernacular Names

Acacia celester (Spanish), Flambouyant bleu (French), Carobaguaçu (Brazil), Mimosenblättrige (German).

Agroecology

J. mimosifolia is a plant from tropical and subtropical areas, generally found growing in drier or mesic areas, grasslands, bushlands, riverine forests and other riverine habitats, also in forests and in protected places such as in ravines. It grows best in highland areas up to 2400 m with annual rainfall of 900-1300 mm, but will also tolerate rainfall of up to 2000 mm. Annual daytime temperatures are in the range of 20 - 34 °C, but can tolerate 10 - 38 °C. J. mimosifolia likes a sunny position, but is not frost tolerant. It grows well in well-drained sandy loam soil, although it can survive in poorer shallow soils. Likes soil with a pH in the range of 6.5 - 7.5, tolerates 6 - 8.5. J. mimosifolia does not tolerate waterlogged or clay soils. However, established plants are drought tolerant.

Morphology

• Barks - is thin and grey-brown. Twigs are slender, somewhat zig-zag and light reddish-brown in colour.
• Leaves - are bipinnately compound and 15-30(-40) cm long, with 13-31 pinnae, each with 10-41 sessile leaflets, (3-)5-10(-12) mm long and (1-)2-3.5(-4) mm wide, oblong, glabrous or slightly puberulent along the midrib and margins.
• Flowers - are described variously to be blue-violet, lilac, lavender-blue or mauve in colour. They occur in open, terminal panicles, the branches puberulent, calyx reduced, broadly campanulate, 5-toothed, the teeth around 1 mm long. Corolla purplish blue, the tube white within, 2.4-5.2 cm long, 0.7-1.2 cm wide at the mouth, pubescent externally and within at the level of the stamens. 
• Fruits - Capsules drying reddish brown, compressed-orbicular, 3.2-5.8 cm long, apex often shallowly emarginate, base truncate to subcordate.
• Seeds - 0.9-1.2 cm long, each surrounded by a thin membrane acting as a wing, more or less surrounding the seed body.

Cultivation

• Propagated by seeds - no pre-treatment is required. The seed should be sown fresh for best germination results - fresh seed soaked in water for 24 hours takes 10 - 12 days for germination, which continues for up to 2 months. Germination rate is 50 - 92%. Planting should be from container stock during cool weather; 8 - 10 months should elapse before plants can be transplanted to the field. The tree is a prolific seeder. Viability is maintained for at least 12 months in open storage at room temperature.
• By cuttings of semi-ripe wood with a heel, rooted in sand. Keep shaded until well rooted. The plants can be raised from branch cuttings.

Chemical Constituents

Triterpenes, flavonoids, acetosides, quinine, phenylpropanoid derivatives, flavonol glycosides, isoquercitrin, fatty acids and anthocyanins, tannins, saponins, steroids, phenylethanoid glucosides, jacaranone.

Traditional Medicinal Uses

• The bark and roots are used in the treatment of syphilis.
• The leaves are used as a vulnerary.