Karroo Thorn, Cape gum
Vachellia karroo

Family: Fabaceae

What it is like

An evergreen shrub or small tree. It grows to 5 m tall and 3 m wide. It can be 15 m tall. The stem is erect. It has spines. The spines are silvery white with a black tip. The spines or thorns can be 7 cm long. The bark is rough and grey-black. The bark peals off to show a rust red colour underneath. The branches are spreading. The leaves (phyllodes) are grey and divided twice. They are 10 cm long. There are 8-20 pairs of leaflets. The flowers are pale yellow. They have a sweet smell. They flowers occur in dense clusters. The pods are 12.5 cm long and narrow. The pods curve to a sickle shape. When ripe they are dark brown.

There are about 1,350 Acacia species. Over 1,000 occur in Australia. It can become a weed. Also as Mimosaceae.

Where it is found

This is a native of Southern Africa. It prefers light to medium soils They need to be well drained. It requires a sunny protected position. It can resist drought and frost. It grows in areas with an annual rainfall between 50-1,500 mm. It grows between 3-2,400 m above sea level. It grows in coastal scrub and woodland and along streams. It can grow in arid places. It suits hardiness zones 9-11.

Countries/locations it is found in

Africa, Angola, Australia, Botswana, Central Africa, Cyprus, East Africa, Egypt, Eswatini, Europe, Lesotho, India, Iraq, Libya, Malawi, Mauritius, Mediterranean, Middle East, Morocco, Mozambique, Namibia, North Africa, Portugal, South Africa, Southern Africa, Spain, St Helena, Swaziland, West Africa, Zambia, Zimbabwe

How it is used for food

The tree oozes a clear red-gold gum which is chewed. It is sweet and eaten by children. The seeds are roasted and ground then used as a substitute for coffee. The inner bark is chewed.

The gum is chewed especially by children.

Edible parts

Seeds - coffee, gum, bark, roots, seeds, leaves - coffee

How it is grown

It is grown from seed. The seed needs to be treated to break the hard seed coat. Normally this is by putting the seeds in very hot water and letting the water cool down overnight then planting the seeds immediately. Seeds grow quickly. Seeds germinate in 3-12 days and can be transplanted when young.

Plants are fast growing.

Its other names

Local names

Cape gum, Doorn Boom, Isinga, Mfungu, Mimosa, Mkwangwa, Moangala, Mooka, Mpampa, Mubayamhondoro, Muhunga, Munenje, Mupfamutshena, Muunga, Muye-nyewe, Muzunga, Soetdoring, Sweet thorn, Umnga, Umunga, Witdoring

Synonyms

Acacia dekindtiana A. Chev.; Acacia eburnea sensu auct.; Acacia inconflagrabilis Gerstner; Acacia horrida sensu auct. mult. non (L.) Willd.; Acacia karroo Hayne; Acacia natalitia E. Meyer; Confusion about these: Acacia pseudowightii Thoth.; Acacia roxburghii Wight & Arn.; Acacia campbellii Arn.; Mimosa eburnea L. f.; Acacia minutifolia Ragnup.; Acacia hirtella E. Mey.;