During a chance visit to an unfamiliar nursery we came across a graceful little tree with dainty white to pink, sweetly-scented flower spikes set against small, dark-green compound leaves. We were told that it was a River Indigo (Indigofera jucunda) – a name that added to its allure! Of course we purchased it to add to our well-treed garden. After investigating its origins I discovered that it grows naturally in riverine forest or scrub from the Eastern Cape north into KwaZulu-Natal.
The genus Indigofera, a member of the pea family, grows all over the world in the tropics and subtropics and comprises over 700 species. The name means ‘bearing indigo’ – with the most well-known species being Indigofera tinctoria which grows in the East Indies and from which a blue dye is extracted from its roots and leaves. This is one of the oldest known colouring agents and has a long history of trade between the East and Western Europe. It was at first so precious that only royalty and the nobility could afford the dyed cloth. However by the 19th century it was being imported to the Cape and available for general sale as can be seen in this advert from the Cape Town Gazette in 1807 placed by the Metelerkamp family’s ancestor, Rutgerus Metelerkamp, who was a merchant in Cape Town at that time.
Another member of the genus, the shrub Indigofera erecta, is the host plant of the Brenton Blue butterfly. I wonder if any butterflies survived the terrible fires in 2017. Apparently the larvae feed on the rootstock of the shrub, so hopefully were safe while the fire raged over them. Interestingly, as soon as we had carried our new little River Indigo into the garden and were trying it out in various positions, a Common Blue butterfly arrived and was obviously delighted to welcome the new arrival, flitting enthusiastically from flower to flower. The flowers are rich in nectar and attract many insects, which in turn attract birds. The tree flowers from December to April, after which reddish-brown seed pods are produced. Apparently the flowers last well in a vase, but our tree is too little to allow any picked flowers yet.
The tree is semi-deciduous and prefers a warm sunny position although it also grows in semi-shade. It grows easily in good, loamy soil. The roots are not aggressive and it does well in containers. Some suggest planting several specimens in a small grove so as to make more of a show. Branches should be trimmed in winter to encourage new growth and abundant flowers. Altogether an enchanting addition to our garden!
Contributor: Leonie Twentyman Jones
Photos: Leonie Twentyman Jones