Tree it may reach 8m. Leaves are simple. Red, bisexual and regular Flowers in racemes are 5-merous with 10 filaments. Fruit is a wingless, hard, dark brown, 1 Seeded nut.
Combretum bracteosum, Poivrea bracteosa.
RSA Tree No. 532.2.
Common names: hiccough nut, hiccup-nut – reason this name is not certain.
Family: Combretaceae (Bushwlillow family). In this family, there are about 16 genera, which contain about 530 species. In the RSA, there are 5 genera and 41 species. The RSA genera with trees are Combretum, Lumnitzera, Pteleopsis and Terminalia. The simple and usually entire Leaves lack stipules. Flowers are usually bisexual. There are usually twice the number of stamens as sepals or petals. The inferior Ovary has 1 locule and usually only 1 of the ovules develops into a seed. Fruit is usually indehiscent and may be winged or ridged.
Name derivation: Combretum – a climbing plant – referring to some species. bracteosum – having clear or numerous bracts at the base of the calyx.
Conservation Status: L C. (Least Concern).
Description: The Tree may reach 8m high but it is usually a multi-stemmed, shorter Shrub, which can spread to about 5m. The Stems are usually unbranched. Bark is light brown and may flake slightly. The side branches are long, narrow and may be armed with thorns up to 1,5cm long. These thorns develop and harden from persistent Petioles (leaf stalks – photo 258). These and the tendency of the young branches to twine, help them to coil and climb.
The ovate to broadly elliptic Leaves are simple (have a single blade which may have incisions that are not deep enough to divide the leaf into leaflets). They are up to 10 x 5cm and are opposite or nearly so, or alternate or whorled. Leaves are dull green on both sides or slightly lighter below. They may be hairy. The 7-8 pairs of Lateral Veins curve up towards the apex where they may loop into each other. The lateral veins do not reach the margin. These veins are indented above and prominently protruding below. Here hair-tuft Domatia (a tiny chamber produced by plants that house arthropods. To the naked eye, each domatium appears as a small bump) may appear in vein axils. The tapering to rounded Apex is may have a sharp tip (photo 261). The Base either tapers or is rounded. The hairy Margin is entire (with a continuous margin, not in any way indented) and may be rolled under. The Petiole (leaf stalk) is up to 1cm long and hairy. In autumn, the leaves change to reddish purple.
The bright red to orange Flowers are bisexual and are actinomorphic (regular, symmetrical. Perianth, the calyx and corolla, are divisible into 3 or more identical sectors). They are grouped together in short dense Racemes (simple, elongated, indeterminate inflorescence with stalked flowers), which occur in leaf axils near the tips of branches. This is a special “tree” when flowering and is visible from a distance. Individual flowers are and about 0,6cm in diameter. The Calyx is green to purplish and has 5 Sepals. The Corolla has 5 Petals. These petals, together with the protruding 10 filaments (in 2 whorls) and the styles give the flower its impressive colour. Most local Combretum flowers have the calyx and corolla in 4’s with 8 Stamens. In Combretum bracteosum the sepals and petals are in 5’s and there are 10 stamens. The Pedicel (stalk of a single flower in a cluster) is about 6mm long. From the base of the pedicel, two clearly visible bracts arise. Flowers have bright red petals, filaments and styles and thus differ from other Combretum species. The single Pistil has a single locule within an inferior Ovary and a protruding style (Sep-Oct).
The smooth, indehiscent, one-seeded hard, spherical Fruit lacks wings and is a Nut (an indehiscent, 1-seeded hard bony fruit). This lack of wings is unusual for local species of Combretum. The fruit is about 2cm in diameter and frequently has 4-5 ridges. It changes from green to reddish and ultimately to dark brown when mature. (Dec-Mar+).
Distribution & Ecology
This tree in endemic (endemism is the ecological state of a species being unique to a defined geographic location) in the RSA. Plants naturally occur close to the sea but do extend inland to about 1 200m. It is common on forest margins and in dune forests: Eastern Cape to KwaZulu-Natal (East London to Richards Bay). A Butterfly – the Striped Policeman (Coeliades forestan var. forestan) has yellowish-white larvae, which feed on the Leaves (and those of some other plants). Adults are mainly brown and white and have a striped abdomen. These butterflies are found from the Eastern Cape northwards to Zimbabwe and Botswana.
Propagation. The Seeds need to be soaked overnight after breaking them out of the hard-outer shell of the fruit. Extracts from mature Leaves can to inhibit the corrosion of mild steel by sulfuric acid – to a reasonable extent. This was tree of the year in 2004. These plants seem to be able to withstand light frost and are happy in a coastal environment. The roasted Nuts are edible.
Boon, R. 2010. Pooley’s Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.
Coates Palgrave, M. 2002. Keith Coates Palgrave Trees of Southern Africa, edn 3. Struik, Cape Town.
Lawrence, G. H. M, 1951. Taxonomy of Vascular Plants, The Macmillan Company, New York. Tenth Printing 1965.
Palmer, E. & Pitman, N. 1972. Trees of southern Africa, Balkema, Amsterdam, Cape Town.