Olinia ventosa

General Info – summary

This Tree is up to 25m high.  Wide straight trunk with high up branches becomes rough & flaky.  Simple, decussate Leaves have entire margins, short petioles and rudimentary stipules.  Regular, tubular Flowers are very small, pinkish, bisexual, in cymes with inconspicuous sepal lobes.  Galls may distort plant parts.  Fruit is a false drupe with a circular scar.  Many small seeds have a thick warty testa with no endosperm.

Description

Previous Names: Olinia acuminata, Olinia capensis, Olinia cymosa, Plectronia ventosa.

SA Tree No. 513.

Common names: (Afr) Hardepeer, Rooibessieboom.  (Eng) Hard–pear.  (isiXhosa) Umnonono, Umngenalahla, Unkunye, Ungenalahle, Inqudu, Umpanzi.  (isiZulu) Ingobamakhosi, Ongenalahle.

Family Oliniaceae.  This is an African family of one genus and ten species (5 in the South Africa).  The trees or shrubs may be deciduous.  They have 4-angled branchlets.  The entire, simple, hairless Leaves are opposite, and petioles are present.  The small, actinomorphic flowers are bisexual.  The petal-like, conspicuous Calyx is 4 or 5 lobed and may be white or pink.  The 4-5, small, hairy Petals are shorter than the sepals.  4 or 5 Stamens with short filaments are present.  The inferior Ovary extends with a straight style and ends with a thickened stigma.  The Fruit is almost spherical and up to 1cm wide.  It is drupe like and turns red to brown when mature.  Seeds have a warty testa and lack endosperm.

Name derivation: Olinia named after Johan Hendrik Olin (1769-1824), a Swedish botanist and author.  ventosa – windy, light or swift which may refer to the growth rate.

Conservation: National Status: L C. (Least Concern).  Assessment 2018/11/08. (L. von Staden).

Tree

When growing on dunes or close to the sea, the plant may remain a shrub.  On young branches (photo 792) the young Branchlets are 4-angled (usually applied to branches of the current or preceding year).  The young bark changes from green to pinkish then grey (photo 785 – under Leaves).  The Bark is initially thin, light to dark grey and smooth (photo 781).  It may have a reddish tinge and may be scaly.  With age, it may become fluted (grooved, funnelled, channelled: having or marked by grooves), rough and flaky (photo 331).  In a forest the tall Tree is up to 25m high, and the trunk may reach a diameter to about 1m.  In favourable conditions young trees are upright (photo 792).  The Bole (is the stem and main wooden axis of a tree) of a tall tree may become buttressed (woody extensions from the tree base that radiate outwards).  In a tree, the Trunk is straight, upright and the initial lower branches tend to fall early, leaving current branches higher up (photo 339).

Leaves

On this evergreen tree, the glabrous (hairless) Leaves are simple (have a single blade which may have incisions that are not deep enough to divide the blade into leaflets).  On the squarish young branches, the leaves are decussate (opposite pairs of leaves have successive pairs at right angles to each other i.e. rotated 90 degrees along the stem when viewed from above).  This can be seen if you look carefully at photos 785 and 787.  Each leaf is up to 8 x 3,5cm and obovate (like an upside-down egg with the narrower end near the base), to elliptic or oblanceolate (the leaf is broader at the apical third than at the middle and tapers towards the base – photo 334).  The Apex tapers and is bluntly pointed, round and may be slightly notched on mature leaves.  The Base tapers into the Petiole (leaf stalk – photo 785).  The petiole is short (up to 7,5mm long), hairy and may be pink and velvety.  The Blade is dark green and glossy above and is lighter and dull below (photo 334).  The slightly wavy Margin is slightly rolled under and the leaf is entire (with a continuous margin, not in any way indented).  The Midrib protrudes below and is mostly sunken above (photo 334).  Veins are slightly easier to distinguish on the lower side and are more clearly visible when viewed against the sun (photo 335).  Here the side veins start at an angle. They divide and bend more steeply before approaching the margin.  Stipules (basal appendages of the petiole) are rudimentary and not clearly visible.

Flowers

The very small, slightly sweetly fragrant Flowers are white – occasionally tinged with pink.  The tubular flowers are actinomorphic (Regular, symmetrical.  Flowers are vertically divisible into similar halves by more than 1 plane passing through the axis).  They are borne in leaf axils towards the ends of branches in short trichotomous (division into 3) Cymes (a broad, more or less flat-topped, determinate flower cluster, with central flowers opening first) which are up to 7cm long.  Each inflorescence may be slightly shorter than the leaves.  There are 3 groups of 3 flowers per inflorescence.  Each flower is on a distinct Pedicel (stalk of a single flower – 3 photos under Fruit).  The creamy-white Bracts (modified leaf associated with reproductive structures) may be mistaken for petals and fall as the flower opens.  Flowers are bisexual.  The Sepal lobes are inconspicuous and occur on the rim of the Hypanthium (the cup-like receptacle derived usually from the fusion of floral envelopes and androecium, and on which are seemly borne the calyx, corolla and stamens).  The minute, incurved, elliptic, white/pink Petal lobes arise from the throat of the tube.  The petals now become reflexed and enlarge exposing the usually 5 Stamens with very short Filaments (the usually long slender stalk that supports the anther).  Each Anther (where the pollen grains are formed) is small and has 2 thecae (pollen sacs) which open by longitudinal slits.  There is a single Pistil (a unit of the Gynoecium, the female element of the flower, composed of the Ovary, Style and Stigma).  The Ovary is inferior (one which is seemingly below the calyx.).  The Style (part of the pistil situated between the ovary and the stigma) is straight and has a thickened Stigma (the part of the pistil that receives the pollen.  (May-Nov).  Galls (in plants are abnormal outgrowths of plant tissue caused by parasites like fungi, bacteria mites and insects seeking nutrition) may distort the flower size and constituents.  (May-Oct).

Fruit

The hard round decorative Fruit may only develop every 5-7 years.  The fruit is an almost spherical false drupe, which is thinly fleshy, 0,5 – 1cm in diameter and turns red to coral pink and finally brown when mature (photos below).  The apex of the fruit carries the circular scar, which is the remains of not just the Calyx but of the hypanthium (an enlarged flower receptacle with sepals, petals and stamens on its rim: photos 789 & 790).  The several small Seeds within the fruits have a thick warty testa (seed coat) and lack endosperm (the starch and oil-containing tissue of many seeds; often referred to as the albumen).  Dec-Jun)

Distribution & Ecology

This is not a pioneer plant (a hardy species which is the first to colonize new or previously disturbed areas) but follows shortly afterwards.  Provincially these trees occur in the Western Cape (e.g. Knysna forests) and along Table Mountain (impressive specimens), roughly to East London in the Eastern Cape – also in the Tsitsikamma National Park (between Knysna and Port Elizabeth).  This plant is Endemic in South Africa (Endemism is the ecological state of a species being unique to a defined geographic location).  It is more common within the low altitude range 90-600m and grows well in kloofs and stony soil.  In the Forest, this is one of the fastest growing of our indigenous trees.  It is often a canopy tree.  Close to the sea it may be reduced to coastal shrub.  Identification of this genus is aided by the smell of almonds that can be found in crushed leaves, young stems, recently cut bark and sapwood.  Insects and birds including Red-faced and Speckled Mousebirds, Bush Doves and Turacos (Loeries) seek the nectar and fruit.

Ethnobotany

The Wood is strong, hard, dense and compact.  It is a yellowish to reddish brown colour.  Seasoning the wood is necessary to avoid splitting and warping.  It was used to build ox wagons.  More recently, it has been used for poles, musical instruments, railway sleepers and for making good furniture.  The wood has a fine finish with a rippled effect.  Heartwood may have dark streaks.  In old trees the heartwood trees may be unsound.  Because of the hard covering, Seeds will take a long time to germinate.  Scaling them beforehand will help.  Under good conditions, the trees are relatively quick growing – more than 1m per year.  This hardy tree will make a good shade tree for a large garden.  Because of its aggressive roots, it should be planted well away from buildings.  Newly cut wood and crushed Leaves have an almond smell, indicating the presence of a compound containing Cyanide.  The plant stores this safely in cell Vacuoles (a vacuole is a membrane bound oranelle within a living cell).

References

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.

Ginn, P.J. McIlleron, W.G. Milstein, S. 1989. The Complete Book of Southern African Birds. Struik Publishers (PTY) LTD. Third impression 1991.

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.

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

von Staden, L. 2018. Olinia ventosa (L.) Cufod. National Assessment: Red List of South African Plants version 2024.1. Accessed on 2025/10/10.

 

http://www.plantzafrica.com/plantnop/oliniavent.htm

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

http://www.platbos.co.za/indigenous_hard_pear.html

http://www.operationwildflower.org.za/index.php/component/joomgallery/trees/olinia-ventosa-thabo-5-4767

http://posa.sanbi.org/flora/browse.php?src=SP