The four buds, unequal in size, have not had a chance to open before this Hoodia gordonii stem-tip started growing again.
Below the buds the spines are dry and dead, above them purplish and supple, alive with juice. Each spine base widens fairly abruptly into its tubercle, serving as its foot or plinth and succeeding in line to form a stem ridge.
In picture it appears as if a different opaque surface starts, almost like an enveloping bract but inside the skin, over the lower part of the young tubercle. This part has to be more durable for the dry days to come. It is the rigid face of the surviving stem over the years of its life, although spines drop off and flowers emerge further up.
Tiny, pinkish beginnings of more flower buds can be discerned among the young tubercles (White and Sloane, 1937; Shearing and Van Heerden, 2008; Le Roux, et al, 2005; iNaturalist).