No, it’s not old age, it’s drought! Some years seasonal, sometimes for years on end.
This Anacampseros telephiastrum plant is consuming its stored succulence, gradually becoming wrinkly in the process. This is something to do while waiting for rain or the miraculous watering can that appears in visitations to the privileged few in the unnatural world of gardens.
Anacampseros is not alone in living like this: all succulent plants store moisture and nutrients for use in times of need, like people remembering to take the water bottle along on hikes. Sucus (Latin) means juice or sap, the sought-after substance needed by all, especially in rainless times and arid regions.
Moisture storage occurs in leaf and stem succulents, as well as in geophytes endowed with storage organs like underground bulbs, corms or tubers. People store things for rainy days, plants for the not so rainy days. Some succulents are adapted to capitalise on alternative climatic sources like mist and dew where rainfall is low and temperatures become high, particularly deserts and semi-deserts.
Plants have evolved numerous solutions for dealing with thirst: smaller leaves, the absence of leaves, modified leaf-shape (cylindrical or spherical), stems replacing leaves for photosynthesis, fewer stomata, modified growth forms (compact, cushion-like or columnar), surface ribs, waxy or hairy coats, roots close to the surface for accessing minimal inundation, thick skins and growing mucilaginous, water-retaining substances inside.
Adaptation is like intelligence, the ability to live effectively in relation to the challenges of the environment (Wikipedia).