Zanthoxylum capense trunk

The pale bark upon an old stem of the small knobwood tree is different to the reddish brown of the young stem, also shown in this Album.

The large swollen knobs or stem mounds that started off as spines only are characteristic of the old stems. Old knobs lose their cone-shapes as seen here (and sometimes also their spines). The knobs then become deformed as they continue growing into various ovoid to hemispherical shapes.

Some pale lichen renders this trunk whiter in patches (Coates Palgrave, 2002).