The plant family Apocynaceae was named and described by Antoine Laurent de Jussieu in Genera Plantarum in 1789.
All the plants I have grown or that are wildflowers on the farm that were members of the plant family Asclepiadoideae (the Milkweed Family) are now members of Apocynaceae. It is strange that Huernia and Stapelia are in the same family as the Asclepias. Of course, there are many genera of succulents, perennials, and trees (ETC.) in this HUGE family… I suppose they have a few things in common we can see at a glance.
Plants of the World Online listed 367 genera in the plant family Apocynaceae when this page was last updated on 8-9-21. Those numbers could change as updates are made by POWO (and likely will).
You can click on the plant names in the caption under the photos to go to the plant’s page.
I was finally able to take photos of the Ascpelias syriaca flowers on June 16, 2021.