General Info

Tree has a straight trunk up to 20m high. Bark mottled, patchy and flaking. Simple, glabrous, entire Leaves are shiny above. The bisexual and actinomorphic Flowers in lax racemes. Red calyx resembles petals. Corolla is tiny.  Fruit: false drupe.

Description

Olinia emarginata

RSA Tree No. 514

Common names: Mountain Hard Pear, Berghardepeer, Rooibessie.

Family: Oliniaceae. This is an African family of 1 genus and 10 species (5 in the RSA). 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 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. He was a student of Thunberg and an author. emarginata – notched – referring to the leaf apex.

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

Tree

This 5 to 20m in high Tree usually has a straight Trunk with a rounded glossy green Crown. This crown is often wider than the height of the tree. It can also be multi-stemmed shrub. The Bark is smoothish, grey to brownish yellow, mottled, patchy and flaking off in pieces to reveal creamy yellow underbark. This Bark is visible from a distance. Branchlets (usually applied to branches of the current or preceding year) are upright, smooth pale white to slightly red. They are distinctly 4-angled and squarish.

Leaves

The opposite, oblong to elliptic to ovate Leaves are glabrous (hairless), simple (has a single blade which may have incisions that are not deep enough to divide the blade into leaflets). It is up to 4,4 x 2cm and may have pink tinge. Upper surface of leaves on this evergreen tree is glossy dark green and shiny. Lower surface is much lighter. Net veining is more visible on the undersurface. Lateral veins loop once before reaching the margin. The Midrib may be reddish. Veins are slightly sunken above and the midrib protrudes below. The Apex is tapering to a rounded, and square or notched at the end. The Base is narrowed and tapering and may be tinged with red. The Margin is entire (with a continuous margin, not in any way indented but may be hairy) and slightly rolled under. If present, the Petiole (leaf stalk) is very short and pink to red in colour (photo 903). Stipules (basal appendages of the petiole) are rudimentary or absent. Crushed leaves have a faint smell of almonds indicating the presence of cyanide.

Flowers

The slightly sweetly scented Flowers are bisexual and actinomorphic (regular, symmetrical. Perianth, the calyx and corolla, is divisible into 2 or more identical sectors). They are in loose, many flowered, terminal heads, which extend from leaf axils. The Bracts (modified specialised leaf usually found with inflorescences and flowers) are opposite and may be up to the length of flowers. The flowers are in lax Racemes (simple elongated inflorescences with stalked flowers). Each small flower is 1-3cm long. The Calyx has 5 or 6 conspicuous pink Sepals which resemble petals. The Corolla usually has 5 or 6 tiny, incurved Petals that are deep pink and each may be tipped with white. They alternate with, and are much shorter than, the sepals. They become spreading and reflexed at anthesis (the period or act of expansion in flowers, especially the maturing of the stamens). The 5 Stamens arise in the calyx tube below and alternate to the petals. Stamens have short Filaments. Each Anther 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 inferior Ovary has fused Carpels (foliar units of a compound pistil or ovary). There are about 3 ovules in each Locule (compartment within an organ e.g. ovary). The Style is straight and ends with a thickened Stigma. (Oct-Feb).

Fruit

The almost spherical Fruit is a false Drupe. This is about 1cm long. In autumn when the drupes matures, they turns from green to a spectacular bright red mass. Fruit is borne in dense clusters and each fruit is slightly fleshy. A circular scar occurs at each fruit apex. This is the result of the remains of flowers cup like receptacle (photo 886). The remains of the style may also be visible. One Seed develops in each locule. Seeds have a thick, brown warty testa (seed coat). No endosperm (the starch and oil-containing tissue of many seeds; often referred to as the albumen) is present. (Mar-Jul).

Distribution & Ecology

These Trees can withstand frost but not drought. They can be found in inland montane forests, close to rocks and streams and grow up to an altitude of 2 100m. Trees can be found in Queenstown in the Eastern Cape, Free State, KwaZulu-Natal – Royal Natal, Golden gate; Gauteng – Pretoria, Magaliesberg; Limpopo. They are also found in Lesotho, Swaziland and Zimbabwe. Birds eat the Fruit.

Ethnobotany

Wood is hard and heavy. The Tree is very difficult to grow but it is very attractive when in full flower. It makes a good bonsai.

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.

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.

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.

http://redlist.sanbi.org/species.php?species=2944-2

http://biodiversityadvisor.sanbi.org/wp-content/themes/bst/keys/seed-plants/Families/F_Oliniaceae.html

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

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

http://www.calflora.net/southafrica/plantnamesH-O.html