General Info

Deciduous Tree to 20m and branchlets have prickles. The Leaves trifoliate. Reddish Flowers are bisexual and zygomorphic. Fruit is a pod, constricted between orange to red Seeds.

Description

Tree

Erythrina caffra, Erythrina constantiana, Erythrina fissa.

RSA Tree No. 242.

Common names: Coastal Coral-tree; Coral tree; Cape Coral-tree.

Family: Fabaceae or Leguminosae are Angiosperms (flowering plants) and commonly referred to as the pea, bean or legume family. After the Orchidaceae and the Asteraceae, the Fabaceae is the third largest Angiosperm family with 700+ genera and close to 20 000 species. Local genera include: Acacia (Vauchellia, Senegalia), Albizia, Bauhinia, Bolusanthus, Burkea, Colophospermum, Cyclopia, Erythrina, Erythrophleum, Indigofera, Philenoptera and Schotia. The Fabaceae are recognisable by their fruit and by their pinnately compound Leaves. Leaves may also be simple and usually have stipules – some of which may be spinescent. Leaflets are usually entire. Flowers are bisexual and bracteate. Regular flowers usually have 4-5 sepals and the same number of petals. Irregular flowers have 4-5 sepals and 5 or less petals. Stamens have anthers that have 2 pollen sacs and there are usually at least twice the number of stamens as petals – often 10. The superior Ovary has one locule that may contain 1 or more ovules. The Stigma and Style are simple. The single carpel develops into the Fruit, which is usually a pod. The pod dehisces on both sides and may break into segments. Seeds vary.

Name derivation: Erythrina – from the Greek “erythros” meaning red: referring to the flowers. caffra – south eastern Cape. The genus Erythrina has about 160 species with 9 in southern Africa and 6 in the RSA.

Conservation Status: L C. (Least Concern). Assessment Date: 2009.

Tree is up to 20m high but usually smaller. This height is environmentally dependant. It has a spreading rounded crown. In the Stem (main axis of the plant, the leaf and flower bearing as distinguished from the root bearing axis), the pale Bark has longitudinal fissures and short prickles or knobs. Branchlets have prickles.

Leaves

The Leaves on this deciduous tree are large and trifoliate (compound leaf with 3 leaflets). The leaf size of the terminal (or central leaflet) is slightly larger and up to 16 x 18cm. The broadly ovate to elliptic Leaflets taper towards the apex. Leaflets have a pair of glands at the base. The Margin is entire (with a continuous margin, not in any way indented). The young Petiole (leaf stalk) lacks prickles. Stipules (basal appendage of the petiole) fall early. Bracts (modified leaf associated with reproductive structures) are present. Veins cam best be seen when the leaf is observed against a strong light (photo 145)

Flowers

The Flowers are most impressive. They are large, bisexual and zygomorphic (irregular flower: when corolla is divisible into 2 equal halves in one plane only). The flowers are 5-merous (floral parts in 5’s). They occur in dense broad racemes (a simple elongated inflorescence with stalked flowers that open in succession towards the apex). These racemes may contain up to 80 individual flowers. The Calyx is grey/brown and its base is tubular. The Corolla has petals that range from orange to scarlet and some trees have flowers that are cream coloured. Here the conspicuous vexillum (the standard or banner petal; the broad upper petal) is broad, short and reflexed so that the stamens are visible. This is one of the main differences between Erythrina caffra and E. lysistemon. The latter has a longer, narrower vexillum which folds and encloses the stamens. The 2 Wing petals and the 2 joined Keel petals are up to 2,5cm long. The 10 Stamens have uniform anthers. The stalked Ovary has an incurved Style and contains many ovules. The flowers usually appear before the new leaves. The flowers are odourless and the tree is insect and bird Pollinated – attracted by the nectar. (Jun-Sep).

Fruit

The Fruit is a dehiscent, hairless, large and dark coloured cylindrical Pod up to 6cm long. It is deeply constricted between the seeds. Older seeds are orange or bright red with a black area around the Hilum (scar or mark left on the seed coat indicating the place of attachment to the ovary wall). (Oct-Dec).

Distribution & Ecology

Commonly found in coastal forests in deep sandy soil and near rivers along the Indian Ocean coastal region in frost-free areas. Places where it is naturally found include the Eastern Cape from slightly east of Port Elizabeth, KwaZulu-Natal and Mozambique. Old wood is soft and is an ideal nesting place for woodpeckers and barbets. The trees can withstand some frost. They do not form a dense shade and this allows other plants to grow beneath them. The tree has been introduced into India and is the official tree of Los Angeles, USA.

Ethnobotany

The low-density Wood is light and spongy and used in small boat building and fishing floats. Seeds have been used for necklaces. Before planting the seeds, soak them in warm water for a couple of days. Select those that have sunk, and allow them to dry. This should be done shortly after collecting them. Truncheons (stem cutting from a selected plant – used to produce genetically identically new plants) can also be used for propagation. Plant in full sun. This is an attractive shade tree. The bright red Seeds use for lucky beans and necklaces. They do, however, contain poisonous alkaloids.

References

Boon, R. 2010. Pooley’s Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban. p156

Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town. p398

van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa, Struik, Cape Town. p388.

 

http://redlist.sanbi.org/species.php?species=341-4

http://pza.sanbi.org/erythrina-caffra

https://en.wikipedia.org/wiki/Erythrina_caffra