The dark, bare stem of Strelitzia nicolai growing tilted at an angle in the photo has a smooth surface. It takes this tree-like plant a long time to develop bare, woody stems such as seen here (SA Tree List No. 34).
When the leaves have been discarded the stem surface may also be pale grey. The nodes and scars where the leaves had grown long ago persist as spaced, pale rings. Some belated flaking of papery detritus from the surface is still underway, maybe continually underway, while new vertical cracks have appeared (Coates Palgrave, 2002; www.plantzafrica.com).