Sclerocarya birrea subsp. caffra stem

The typical patchy appearance of the bark on a marula trunk is displayed in the photo. The pale patches appear where the upper layer of the bark peels off. Black lines resembling routes on a map form ragged rings around some peeled and unpeeled patches.

Marula bark features in traditional medicine as a prophylactic and remedy for malaria. An infusion of the bark is also used in alleviating pain from scorpion stings and snake bites. A patients beliefs and expectations form part of the therapeutic process. 

Gum from the stem mixed with soot and water has been used in making ink. Knowledge grows progress (Ezemvelo Rhino Club Newsletter, Nov.2012; Wikipedia).