This Cynanchum viminale is in physically close, if not intimate relationship with a Euphorbia heptagona plant. It is flowering all over its mate in the Kammanassie in April, a celebration of marriage or whatever cross-species partners do.

Both are succulents and the one is a climber. The Cynanchum belongs to the Apocynaceae family, while the Euphorbia is a member of the Euphorbiaceae family, as can be expected. Interestingly enough, both these families are sometimes commonly referred to as milkweeds, based on the milky latex that many members of both families exude when stem or leaf skin is damaged. An affinity of the blood will out, albeit that the blood is white.

Different additional common names are these days in use for both. Apocynaceae is also known as the carrion flower or oleander family and Euphorbia as the rubber tree or spurge family.

Publications only using the botanical or scientific names are, of course, understandable to the knowledgeable, particularly the botanists and scientists working in related fields. Other literature make concessions for keeping the general public, the untrained plant lovers and potential plant lovers in the loop. Using only the common names would be impractical and confusing, as they overlap, are inconsistent and don't name everything; also not intelligible to people speaking different languages.

The future of plant survival is a challenge for which plant lovers, the scientists, amateurs and citizens in general all need to join forces. They need to spread the word, befriend each other, grow the plant affinity and implement the conservation measures. Getting to know plants is a start. 

The C. viminale or caustic vine is matching its Euphorbia partner in much ground-level branching in picture, if it is not only growing multistemmed from ground level. Both plants branch a little higher up as well, their stems differing between thinly cylindrical and angular with spines; unlike but sharing living space (Smith, et al, 2017; Vlok and Schutte-Vlok, 2015; Bean and Johns, 2005; iNaturalist).