Senegalia galpinii old trunk

The lower part of the trunk of a mature Senegalia galpinii tree has lost the flaky and corky features that will still be present higher up on mid-sections of branches below the green, young stem tips. The big, old trees flourishing by the rivers of the old Transvaal may become over 2 m in diameter.

Seen here, it is rough in texture, brown in young patches, grey in old ones and longitudinally furrowed in slightly twisted lines, deviating from the vertical. The tearing in upper layers of the bark that resulted from thickening of the stem is irregular, causing uneven breaks in the upper layers pushed open by the softer lower ones, pliable enough to resist tearing.

Few or no spines remain upon these lower parts of the stems, usually by now positioned quite loosely and removed easily when touched (Coates Palgrave, 2002; Schmidt, et al, 2002).