The lower stems of an old and large Monsonia crassicaulis plant like this one growing in the Hester Malan Succulent Garden of the Goegap Nature Reserve lose their leaves and (most) of their spines.
The smooth bark in shades of brown, grey and green has occasional flaky patches and gnarled spots among the bulges of convoluted lower branches grown obese with age.
Branching started close to the ground long ago, the bulging stem-base huge compared to the overall plant size. Stored moisture found here has so far proved ample for all contingencies over a long life (Le Roux, et al, 2005).