Sacred Coral Tree
Willem says: 'The Phyto-Philes are for plant lovers of every size and shape, colour and flavour. As with my Colours of Wildlife column, I'll be featuring one species per article, illustrated with sketches, paintings, and/or photos. Over time I hope to be showcasing the amazing diversity of weird and wonderful plants that occur in South Africa, while also from time to time looking at the flora of other countries. While featuring many spectacular species, I'll not be neglecting the smaller, more humble kinds that are nevertheless fascinating in their own right.'
This tree, Erythrina lysistemon, is a common and well known tree here in Northern South Africa, and is indeed often called the Common Coral Tree. It is widely planted in Polokwane, and indeed has been planted by peoples living here well before the origins of this city. Today it is planted along streets and in parks, and also in gardens. The photos you see here were taken in Ster Park, my suburb … the very stout one is the largest individual I know of, and grows in Phobos Avenue, the street where I live.
I'm sorry that the trees weren't flowering when I took these photos. I will see if I can catch them in flower someday, and then publish the photos as a Phyto-Philes special! For now, I include here a painting to show the beautiful flowers. The coral tree flowers at the start of spring, when the leaves just start to emerge, the tree sometimes being in full flower even before bearing any leaves, which is a spectacular sight! The flowers are densely packed along the inflorescence, each flower curving outward gracefully. They are rich in nectar and a source of food for many kinds of birds and insects. Coral trees are members of the pea family! They grow quite large, reaching 12 m/40' in height and even more than that in spread. Actually I think the big one in my street exceeds those numbers to a respectable degree!
As you might gather, the sacred coral tree has been highly esteemed by humans for a very long time. Many societies had the custom of commemorating a man, when he dies, by planting a sacred coral tree on his grave. There is also a belief that the chief of a tribe should ritually bathe in water in which the bark of this tree has been soaked. This would then confer authority on him so that he will have the respect of his people. The bark is believed to have many medicinal properties: it is used to treat sores, wounds, abscesses, toothache and arthritis. An infusion of the bark, together with other herbs, is used for easing labour pains. Powdered, burnt bark is applied to open sores. The leaves are used as well: suppurating sores are treated with crushed leaves, and infusions of the leaves are used for earache. A decoction of the roots are used to treat sprains. All of this is interesting when you take into account that Erythrina-species have alkaloid compounds in their tissues that are known to be highly toxic! The trick is definitely in the dosage – so don't self-medicate!
Coral-tree wood is light and soft, not useful for general construction purposes, but canoes, troughs and floats are made of it.
In the wild, the sacred coral tree is generally found in hot, dry regions. Its distribution ranges from the Eastern Cape, where it is found in scrub forest and dune bush, to the Limpopo Province of the north, where it grows in savannah, along rivers, and on rocky hills. It ranges northward into Zimbabwe and from there into tropical Africa as far as Tanzania. In warm regions with well-draining soil, it can grow even where the rainfall is high.
This species has much ecological value. As I said, the nectar-rich flowers attract birds and insects. When the pods follow the flowers, parrots open them to eat the unripe seeds. Many animals browse these trees: elephants, black rhinos and antelopes. Bushpigs and porcupines dig up and eat the roots. Vervet Monkeys eat the flower buds, and the larvae of attractive butterflies feed on the leaves. With so many things eating it, it's a good thing that coral trees are fast and powerful growers and easily recover from damage!
The branches and trunk of the sacred coral tree bear short, stout, sharp spines. The prickly crown is a good, safe nesting site for birds. The soft wood can easily be excavated by woodpeckers and barbets. In the summer, the open canopy throws a light shade in which antelopes and other large mammals can take shelter from the intense sun.
Apart from practical uses, coral trees are very ornamental! Their flowers are lovely and have been represented in South African art for ages. The pods that follow the flowers are black and constricted between the seeds, like beads on a string. The pods can be used as small ornaments, and the seeds themselves are hard, shiny and bright red-orange. They are used as lucky charms! Coral trees can be trained as bonsai subjects, and also grown as container specimens, responding well to pruning.
There are several other species of Erythrina in South Africa. A few are conventional trees, but there is also one that is a miniature tree, and two that form substantial subterranean tubers from which the thin leaf- and flower-bearing stems arise. The pea family in general is ridiculously diverse in South Africa, ranging from tiny herbs to huge trees. Most of them can be easily identified as members of the family by the shape of their flowers and by their pods. Many of them are very hard to identify down to species level, though, because some genera have dozens or even hundreds of species.
Growing Sacred Coral Trees
This is one of the easiest of trees to grow. In most of Europe and the USA it doesn't make sense to grow this as anything other than a bonsai or indoors container plant, but I think it could grow outdoors in the American southwest and perhaps in southern Spain. Of course here in South Africa it can be grown in much of the country, and in my opinion should be grown even more than it is! It can only withstand light frost, but is tolerant of long droughts. The seeds are easily collected from the pods, and are usually undamaged, being quite hard. For best results, soak them in water for 12 hours before planting them. They need a fairly hot environment for best germination, and well-draining soil. They can be germinated in river sand and then transplanted into individual bags as soon as the first true leaves emerge. Coral trees can also be grown from cuttings and truncheons. These should be made from twigs or branches at least a season old, and planted in a sandy medium similar to that used for germinating the seeds. The cuttings strike fairly rapidly, but leave them to grow for a season or two before transplanting them. Coral trees have powerful, spreading root systems and should not be planted close to buildings, pavements or other structures. Unfortunately here in Polokwane this advice is not often heeded and there are many places where the coral tree roots are lifting up slabs of paving stones, cracking walls, and doing other damage because the people who originally planted them didn't realize just how vigorously they would grow. This tree is therefore best suited to parks and large gardens. They grow very rapidly and don't need much watering – although they would respond very gratefully to whatever water they can get! They already start flowering in the second or third season of their lives.