Tree usually up to 2+m high. Bark smooth with lenticels. Simple Leaves with serrations. Bisexual, actinomorphic, yellow Flowers: to 2cm wide. Calyx yellow, accrescent to red. Fruits: small 1-Seeded drupes on the now red receptacle.
Ochna serrulata, Ochna atropurpurea.
RSA Tree No. 479.1.
Common names: Carnival Ochna, Carnival Redwood, Small-leaf Plane, Mickey Mouse bush.
Family: Ochnaceae. This family has about 30 genera and about 250 species. In the RSA there are 2 genera and 13 species. Members are shrubs or trees. The bark may be rough or smooth and may flake. The simple Leaves are alternately arranged and usually hairless. The parallel lateral veins are close together. The regular, bisexual Flowers may be fragrant and may be solitary. The 4-5 sepals are usually persistent and usually pinkish or red when in fruit. Sepals are quincuncial (an arrangement of 5 parts e.g. petals or sepals that overlap in such a way that 2 are exterior, 2 interior and the 5th is has one edge outwards and the other inwards) in bud. The 4-5 fugacious (lasting for a short time) Petals are usually yellow and have short stalks. The number of Stamens varies and the persistent filaments end with anthers that have 2-theca (2 pollen sacs). There are 5-15 carpels. Fruit is a 1-seeded drupelet and rests on an enlarged receptacle.
Name derivation: Ochna – Greek – resembling the wild pear. serrulata – saw-toothed leaf margins.
Conservation Status: L C. (Least Concern). 2009 (Raimondo et al.).
This small Tree is up to 2m and occasionally reaches 6m high. It is often a multi stemmed, much-branched shrub. The smooth Bark is pale brown to grey. Raised, greyish white lenticels (usually raised corky oval or elongated areas on the plant that allow the interchange of gases with the environment) occur on branchlets. Pinkish green rosette like Galls with overlapping, sharply pointed scales may be present on the branches.
The deciduous plant has Leaves that may also be shed in very dry or cold conditions. They are simple (have a single blade which may have incisions that are not deep enough to divide the blade into leaflets), narrowly elliptic and usually up to 5 x 1,5cm. On the lighter, Lower surface of the leaf the Midrib protrudes but the net veins are clearly visible in both sides. The Upper surface is a darker green colour and may be shiny. Here the closely spaced Lateral Veins are visible. The Margin is wavy with sharp, fine serrations. They Apex and Base are narrowly tapering to rounded. The new leaves are a shiny, coppery red. The Petiole (leaf stalk) is very short. Stipules (basal appendage of the petiole) are present between the petioles.
The usually solitary Flowers may be in pairs on small leafless side shoots. Individual flowers are bisexual, actinomorphic (regular, symmetrical. The Perianth, the calyx and corolla, is divisible into 3 or more identical sectors). They are yellow, scented and up to 2cm across. Bud scales / bracts are distichous (arranged alternatively in 2 opposite vertical rows) and shed early leaving transverse scales on twigs. The Calyx has 5 Sepals which are initially yellow until after pollination. They are persistent and become and accrescent (increasing in size with age: like a calyx that continues to grow after the corolla has fallen). As the fruit begins to form, the colour of the sepals changes to a brilliant red or is tinged with orange. In the Corolla there are 5 yellow, distinct (separate: not joined with parts in the same series) Petals which only survive a short while before falling. There are up to 40 Stamens, which are hypogynous (borne on the same torus / receptacle or under the ovary). The Filaments are filiform (thread like). The Anthers have 2 theca (pollen sacs) and open by apical pores (photo 51). There are more than 4 Carpels (one of the foliar units of a compound pistil or ovary) attached to the raised receptacle. A single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma) is present and the superior (one that is free from the calyx or perianth) Ovary has 5 locules (compartments) – each one contains a single ovule. They are borne on a substantially enlarged disc-like receptacle (is that expanded tip of the flower stalk from which the floral parts develop). The initially green (photo 51), persistent Style becomes red (photo 197) and the Stigma splits into 5. (Sep-Nov).
The Fruit has 5 small separate fleshy Drupes (fleshy, 1-seeded indehiscent fruits with each seed enclosed in a stony endocarp; stone fruit e.g. peach) which are borne on the enlarged receptacle. They are initially green but change to yellow and finally black. Below this is the now distinctively red Calyx. The small Seeds lack endosperm (the starch and oil-containing tissue of many seeds; often referred to as the albumen) (Nov-Mar).
Distribution & Ecology
The Tree may occur in Western Cape, Eastern Cape, KwaZulu-Natal, Mpumalanga and Limpopo. It grows in forest margins, bushveld, grassland and even fynbos (a belt of natural shrubland or heathland in the winter rainfall area with the distinctive vegetation of the Western Cape). It is the larval food plant for the Karkloof Emperor (Charaxes karkloof) and Marieps Emperor (Charaxes marieps) butterflies. The Flowers attract Butterflies and bees. Birds eat the Fruit.
These plants have become invasive in Australia but are now grown in Hawaii. Wood is reddish. It is a good garden tree, slow growing and can be grown from very fresh seeds. Established plants can withstand a light frost. It is an attractive addition to a garden and grows best in full sun but can take some shade.
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.
Schmidt, S. Lotter, M. & McCleland, W. 2002. Trees and Shrubs of Mpumalanga and the Kruger National Park.
van Wyk, B. & van Wyk, P. 1997 Field guide to Trees of Southern Africa, Struik, Cape Town.