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Erythrina lysistemon is a lovely, small to medium-sized,
deciduous tree with a spreading crown and brilliant red flowers.
It is a handsome tree at any time of the year, and its dazzling
flowers have made it one of the best known and widely grown South
African trees.
This is a stocky, thickset tree that often branches low down and
usually grows up to 10 m in height, occasionally reaching 12 m.
The bark is smooth and dark gray to gray-brown and is not thickly
corky. Short, hooked prickles are sparsely and randomly scattered
on the trunk and branches. The leaves are trifoliolate (compound
leaves with 3 leaflets), and each leaflet is large, usually up to
17 x 18 cm. The petiole, rachis and the midrib have hooked prickles
on them. The common coral tree blooms in early spring (from August
to September) and it produces its flowers before its new leaves
or just as the leaves begin to show.
The flowers are a beautiful clear scarlet and are carried in short,
dense heads, about 9 cm long, on long, thick stalks. The standard
petal (the large uppermost petal) is long and narrow and encloses
the other petals and the stamens. The flowers produce abundant nectar
that attracts many nectar-feeding birds and insects, which attract
the insect-feeding birds as well.
The fruit is a slender, black pod that can be 15 cm long and is
sharply constricted between the seeds. The pod splits while still
attached to the tree to release bright red 'lucky bean' seeds.
Erythrina lysistemon occurs in a wide range
of altitudes and habitats from North West Province, Limpopo (formerly
Northern Province), Gauteng, Mpumalanga, through to Swaziland and
KwaZulu-Natal, and down to about the Mbashe River Mouth in Eastern
Cape. Further north in Zimbabwe, Botswana and Angola it occurs in
small pockets. It grows in scrub forest, wooded kloofs, dry woodlands,
dry savannah, koppie slopes and coastal dune bush and also in high
rainfall areas.
Uses of Erythrina lysistemon
Erythrina
lysistemon is not just a decorative tree, it is also an important
component of the ecosystem, providing food and shelter for a variety
of birds, animals and insects. Many birds and insects feed on the
nectar. Vervet monkeys eat the flower buds. Kudu, klipspringer,
black rhino and baboons graze on the leaves. Black rhinos, elephants
and baboons eat the bark. Bush pigs eat the roots, and the brown-headed
parrot eats and disperses the seed. Birds such as barbets and woodpeckers
nest in the trunks of dead trees, and swarms of bees often inhabit
hollow trunks.
Erythrina lysistemon is also widely used and enjoyed by
mankind. They have been regarded as royal trees, and were planted
on the graves of Zulu chiefs. They were planted as living fences
around kraals, homesteads and waterholes, and were one of the first
wild trees to be planted in gardens in South Africa. They are still
to be found in many gardens, and are planted as street trees in
many towns. The wood is light and cork-like when dry and has been
used for making canoes, rafts and floats for fishing nets as well
as for troughs and brake-blocks. It has also been used to make shingles
for roofing, as the wood is durable when tarred. The flowering of
the trees has been, and still is, a good signal to the people that
it is time to plant their crops.
Erythrina lysistemon is thought to have both medicinal and
magical properties by many people. A tribal chief will wash in water
in which bark has been soaked as he believes that by doing this
he will ensure the respect of his people. Women about to give birth
are given an infusion of herbs to make the birth easier and a sliver
of bark from the four sides of the tree is tied around the bundle
of herbs before it is boiled. Water in which bark has been soaked
is mixed with the root of a species of Cussonia and used
as a purifying emetic. Crushed leaves placed on a maggot-infested
wound are said to clear the maggots. The bark applied as a poultice
is used to treat sores, wounds, abscesses and arthritis. Infusions
of the leaves are used as ear drops to relieve earache, and decoctions
of the roots are applied to sprains. Erythrina lysistemon
does contain a large number of alkaloids that are known to be highly
toxic, but its use in traditional medicine suggests that they have
antibacterial, anti-inflammatory and analgesic effects. The seeds
are used as lucky charms. According to Braam van Wyk and Piet van
Wyk, who are indigenous tree specialists, the seeds also contain
toxic alkaloids as well as anti-blood-clotting substances that may
be of value in the treatment of thromboses.
Other Erythrina species
There are ± 100 species of Erythrina that occur in the warm
regions of the world. Nine species occur in southern Africa: E.
acanthocarpa, E. baumii, E. caffra, E. decora, E.
humeana, E. latissima, E. lysistemon, E. mendesii and E.
zeyheri. Kirstenbosch National Botanical Garden has excellent
specimens of Erythrina lysistemon, E. caffra, E. humeana
and E. latissima that are very showy when in flower.
Erythrina
lysistemon is often confused with Erythrina caffra, the
coast coral tree. Erythrina caffra grows in the coastal and
riverine fringe forests from Port Shepstone in KwaZulu-Natal to
the Humansdorp District in Eastern Cape and in a pocket further
north on the KwaZulu-Natal coast. It is generally taller than Erythrina
lysistemon, the flowers are orange-scarlet, and a cream-flowered
form is occasionally seen, and the standard petal is shorter and
broader so that the stamens stick out of the flower giving it a
whiskered look. In most other respects they are very similar, and
were in fact regarded as the same variable species for many years
and, when not in flower, are difficult to tell apart.
The genus name Erythrina comes from the Greek erythros
meaning red, both the flowers and the seeds are bright red.
The species name lysistemon also comes from the Greek meaning
'with a loose or free stamen' and refers to the 'vexillary stamen'
that is free from the staminal tube. The vexillary stamen is the
stamen associated with the vexillum, which is another term for the
standard petal, and in this species it is free, whereas in e.g.
Erythrina caffra it is joined to the staminal tube below
the middle.
Growing Erythrina lysistemon
Erythrina lysistemon is a fast-growing, undemanding tree.
It does best in fertile, well-aerated and well-drained soils. It
is fairly drought-tolerant, but performs better if given water during
summer. It is sensitive to cold and grows best in frost free gardens,
but will survive in regions with a winter minimum of -7 to -1o C/20
to 30o F (zone 9) provided it is planted in a sheltered position,
and protected from frost when young. This tree prefers dry winters,
but it will thrive in the wet winters of Western Cape as long as
it is planted in well-drained soil and watered during the dry summers.
Coral
trees are attacked by a boring insect that enters at the tip of
a branch and causes die-back. As soon as this is noticed, the damaged
branch should be cut back to unbored wood and the prunings should
be burnt. It is difficult to control on big trees, but it can be
done with a systemic insecticide. Caterpillars can cause damage
to the foliage, and an insect causes yellowish galls on the leaves,
but these do not seem to affect the overall health or performance
of the tree.
The common coral tree is an excellent specimen tree for gardens
and parks and is very effective planted in avenues or for street
plantings. It is particularly recommended for that spot in the garden
where you need sun in winter and shade in summer.
Erythrina lysistemon is easily propagated from seed, cuttings
and truncheons. Seed is sown in spring and summer, in a well-drained,
general-purpose potting soil, placed in a warm but shaded spot and
kept moist. Soaking the seed overnight in warm (not hot) water is
not necessary for germination to occur, but should hurry things
along. Dusting the seed prior to sowing, or drenching after sowing,
with a fungicide that combats pre-emergence damping off, although
not essential, will increase the percentage germination. Cuttings
are best taken in spring to summer, and truncheons in late winter
to spring. Truncheons are made from part of or even an entire branch
which is left to dry and heal for a few days, then planted into
a pot filled with sand or even directly into the soil where the
plant is to be grown, and kept damp but not wet. If a plant has
to be transplanted, this is best done whilst it is dormant, during
winter.
References
- PALGRAVE, K.C. 1977. Trees of southern Africa, edn 2. Struik
Publishers, Cape Town, Johannesburg.
- PALMER, E. & PITMAN, N. 1972. Trees of southern Africa.
Balkema, CapeTown.
- POOLEY, E. 1993. Trees of Natal, Zululand and Transkei. Natal
Flora Publication Trust, Durban.
- SMITH, C.A. 1966. Common names of South African plants. Memoirs
of the Botanical Survey of South Africa No 35. Department of Agricultural
Technical Services, Pretoria.
- VAN WYK, B-E., VAN OUDTSHOORN, B. & GERICKE, N. 1997. Medicinal
plants of South Africa. Briza Publications, Pretoria.
- VAN WYK, P. & VAN WYK, B. 1997. Field guide to the trees
of southern Africa. Struik Publishers, Cape Town.
- LEISTNER, O.A. (ed.). 2000. Seed plants of southern Africa:
families and genera. Strelitzia 10. National Botanical Institute,
Pretoria.
Authors: Giles Mbambezeli & Alice Notten
Kirstenbosch National Botanical Garden
August 2002
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