The globular green and pale purple fruit of Euphorbia mammillaris more or less cover this stem tip. On short stalks, the fruits are three-sectioned with the remains of the branched styles persisting on top. The female plants produce only cyathia with ovaries and stigmas, so all of them can develop these bulging capsules.
Pollen was produced on different plants in the neighbourhood. Nectar and pollen served as currency or enticement, i.e. pollinator food, ensuring the transportation required for the seed set expected here.
For those that see the Euphorbia genus and the cactus family as “the same thing”, the common name of corn cob cactus for E. mammillaris may be fitting.
This plant was encountered in the stony hills southwest of Oudtshoorn (Euston-Brown and Kruger, 2023; Frandsen, 2017; Smith, et al, 2017; Vlok and Schutte-Vlok, 2010; iNaturalist; Wikipedia; www.redlist.sanbi.org).