Camel Thorn or Giraffe Thorn * Kameeldoring * Acacia Erioloba

https://www.inaturalist.org/taxa/595946-Vachellia-erioloba/browse_photos

The tree can grow up to 20 metres high. It is slow-growing, very hardy to drought and fairly frost-resistant. The wood is dark reddish-brown in colour and extremely dense and strong. The seeds can be roasted and used as a substitute for coffee beans.

The name 'camel thorn' refers to the fact that giraffes commonly feed on the leaves with their specially-adapted tongue and lips that can avoid the thorns.

By Robur.q - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=42942816

Common names by http://treesa.org/vachellia-erioloba/  

• (Afrikaans) Kameel Blom, Grootdoring,  Kameeldoring, Kameeldoringboom, Rooihoutdoring, Swartkameel, Swartkameeldoring, Vaalkameel.  
• (English) Black-barked Camel Thorn, Camel Thorn, Giraffe Thorn, Giraffe Tree, Mimosa, Transvaal Camelthorn.

Read an interesting internal article on the Camel Thorn tree.

Sources:
(*) https://en.wikipedia.org/wiki/Vachellia_erioloba

(*) http://www.plantzafrica.com/plantab/acaciaeriol.html

(*) https://web.archive.org/web/20100705085122/http://www2.dwaf.gov.za/dwaf/cmsdocs/4116___poster%20protected%20trees.pdf

(*) http://treesa.org/vachellia-erioloba/

(*) https://www.inaturalist.org/taxa/595946-Vachellia-erioloba