Olea capensis

Black ironwood
File:Olea capensis - Ironwood Tree - Cape Town 2.jpg
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Lamiales
Family:	Oleaceae
Genus:	Olea
Species:	O. capensis
Binomial name
Olea capensis L.
Synonyms
Olea laurifolia Lam.

Olea capensis (syn. Olea undulata), also known by the common name black ironwood, is an African tree species belonging to the Olive family (Oleaceae). It is widespread in Africa, being found almost throughout Africa south of the Sahara from the east in Somalia, Ethiopia and Sudan, south to the tip of South Africa, and west to Cameroon, Sierra Leone and the Islands of the Gulf of Guinea, as well as Madagascar and the Comoros. It occurs in bush, littoral scrub and evergreen forest.

Olea capensis is known by a variety of common names including:

• Afrikaans: ysterhout
• English: black ironwood, East African olive, Elgon olive, ironwood, ironwood olive
• Swahili: loliondo, mushargi
• Trade names: loliondo, mutharage, mutharagi, olive

File:Giant Ironwood Tree - Olea capensis macrocarpa - Newlands Forest - Cape Town 1.jpg

O. c. macrocarpa, like all races of Black Ironwood, can reach enormous proportions in the wild.

Description

The black ironwood is a bushy shrub, or a small to medium-sized tree, up to 10 metres (33 ft) in height, occasionally reaching 40 metres (130 ft).

• Bark: light grey, becoming dark grey and vertically fissured with age; a characteristic blackish gum is exuded from bark wounds.
• Leaves: light to dark green and glossy above and paler green below; petiole often purplish, 0.3-1.7 cm long; lanceolate-oblong to almost circular, 3-10 x 1.5–5 cm.
• Flowers: white or cream and sweetly scented, small and in many flowered axillary or terminal heads, bisexual, 3–15 cm long.
• Fruit: when ripe they are somewhat succulent purplish drupes; ovoid up to 2 x 1 cm.

Subspecies

The species has been divided into 3 subspecies:

• Olea capensis ssp. macrocarpa: flowers in lax heads, fruits oblong to elliptic.
• Olea capensis ssp. capensis: flowers in dense heads, leaves very variable, apex often rounded, and fruits almost spherical to oblong elliptic.
• Olea capensis ssp. enervis: leaves usually broadly elliptic, apex tapering.

Uses

Food

Olea capensis has masses of sweetly scented bisexual flowers, that produce large edible fruits.

Lumber

The wood of the tree is very hard, fine grained, and heavy, and although difficult to work, it is widely used for art and artifacts.

Gardens

Olea capensis is cultivated as an ornamental tree in parks and gardens.

The Guinness Book of World Records lists this tree as the world's heaviest wood, with a specific gravity of 1.49. It is known for its tendency to sink in water, unlike other wood materials. It is also the one of the world's hardest woods according to the Janka hardness test. The timber has a good abrasion resistance and is very strong. It is an excellent turnery wood, and is used for a wide range of decorative items.

Gallery

• Olea capensis Ironwood tree flowers.JPG

  Olea capensis flowers
• Olea capensis01.jpg

  Timber
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  Leaves
• Olea capensis04.jpg

  Trunk and bark

External links

• AgroForestry Tree Database: Olea capensis