Celtis africana

Description

One of our most popular and rewarding indigenous trees, and also currently a protected species. It is not related to the true Stinkwood (Ocotea bullata) but received its name due to the unpleasant odour that is released from freshly cut wood, and the paleness of the bark. They grow to be magnificent trees, with a fine form that provides lovely, deep shade. A wonderfully picturesque tree, with pale, matt-grey bark and perfectly shaped, almost flawless, fresh, bright green leaves that form a striking contrast to the pastel-hued main stem.

SA Tree

Family

Cannabaceae – the Hemp family of the rose order (Rosales)- Formerly part of Ulmaceae (Elm family).
A genus of flowering plants mainly from the Northern hemisphere, containing 11 genera with somewhat 170 species.
Member include trees, Celtis (hackberries), Cannabis (hemp) and Humulus (hops), and are classified as either trees, erect or twining herbaceous plants.
In SA, 3 genera of trees fitting into this family occur.
All members of this genera have simple, alternate or palmately compound leaves and unremarkable, small and petal less greenish flowers.
Although the male and female flowers differ in appearance, they are most often found on the same tree.

Habitat

Occurs in a wide variety of habitats, from forests, coastal thicket and related sandy dunes, to savannah and occasionally bushveld, woodland and wooded grassland areas, as well as along river and stream banks, but usually associated with high rainfall areas.
From the coast to elevations of about 2000 m.
Occurs in almost all nine South African provinces, extending its reach further north into tropical Africa.

Bark

Smooth, pale-grey, with occasional horizontal ridges.
On older specimens, the bark can often be seen loosely peeling in large strips.
Young stems are covered with a layer of fine, white hairs, giving them a velvety appearance.

Foliage

New leaves are a vivid, bright green, with a covering of fine downy hairs, and as they mature, their colour darkens.
The leaves are simple, somewhat triangular in shape (15-100 x 10-50 mm), broader at the bases, with tapered, somewhat pointy tips, and are alternately arranged.
Three prominent veins can be seen running from the base, and the margins are very finely toothed.

Flowers

Small, rather inconspicuous, star-shaped, yellow-green flowers.
The male and female flowers are separate but occur on the same tree.
Male flowers grow in dense clusters on the ends of branchlets, while female flowers are solitary, or in small groups of 2-3, and grow from the axils of the leaves. (August- October).

Fruit

Height

Spread

Medicinal

The pounded bark is used to treat fevers and headaches.
An essence is extracted from the leaves which is said to provide relief from sore eyes.
The roots are boiled in water, and this infusion is traditionally drunk to lessen severe shaking, treat dysentery, diarrhoea, lessen tooth and ear aches, and kill the cestodes of certain internal parasites.

Practical

The wood is whitish-yellow in colour, tough, strong, heavy but quite difficult to work, and is therefore of little commercial value.
It does however make a good general-purpose timber and has been used traditionally to make a number of smaller household items and furniture.
The fibrous inner bark is used to make sturdy ropes and occasionally pieces of cloth.

Warnings

It has a fairly aggressive root-system and should be planted well away from permanent structures such as buildings, wall, paving and pools.
It is not suitable for planting in confined spaces or small gardens as it grows rather big, and also has a large spread.

Wildlife

The leaves are browsed by game, smaller antelopes and livestock.
It is also the host food plant for the larvae of the beautiful Long-nosed butterfly (Libythea labdaca).
The fruits and seeds are eaten by many bird species, including the endangered Cape Parrot, as well as Vervet monkeys.
The flowers will attract insects, butterflies and bees, which will in their turn attract insectivorous birds.

Advantages

Adaptable, hardy, and requires little to no maintenance.
A fast grower that will provide excellent, cool shade in summer.
It responds well to pruning, and can be trained into a lovely container specimen, and is also a good bonsai subject.
Perfect for farms and reserves, as well as large, open gardens and parks.
A good choice for street sides or parking bays.
Can be grown in saline soils near the coast.

Tolerance

Once established, the trees can withstand fairly long periods with little to no water.
Younger and unestablished trees should however be given water on a regular basis.
It can withstand short periods of mild frosts, but excessively cold conditions may cause some damage.
For the first 2-4 years, they should be adequately sheltered against extreme fluctuations in temperate (severe frosts).

Growth Rate

A fast grower, especially when young, able to grow between 800 -1500 mm per year.

Lighting

Prefers full sun but will accept partially shady conditions. (at least 6-8 hours direct sunlight per day).

Soil & Water

Prefers deep, moist and fertile, peaty or loamy soils, but will accept less favourable conditions.
It will grow in poor, sandy or saline soils, but under these conditions it may only reach shrub height.
It naturally favours areas of high summer rainfall and thus has moderate to high water requirements.
Extra water can be given during the warm summer months, when growth is most active, and when in flower and fruit.

Propagation

Easily grown from seed.
It is advisable to harvest these from the tree as soon as they are ready, because once they fall to the ground they are often heavily parasitized.
Separate the seeds from the fleshy, germination inhibiting pulp prior to sowing.
This pulp is usually removed by the digestive process of birds.
Sow the seeds in a well-drained mixture of fine, washed river sand and compost (2:1), and place in a bright, warm area.
Keep the soil moist, but do not it become waterlogged.
Germination typically occurs within 15-30 days.