The flowers of Hoodia pilifera subsp. pilifera are not here as dark as those of subsp. annulata and lack the raised annulus at the base of the corolla giving that subspecies its name. The flowers become about 2 cm in diameter.
Subsp. pilifera, more known in the Little Karoo, is distributed more to the west, while H. pilifera subs. annulata occurs slightly further east, although the two distributions overlap (iSpot; www.redlist.sanbi.org).