There are so many Oleander cultivars that it's hard to generalize about what the Oleander, Nerium oleander, looks like. The one at the right is a special dwarf type but some other Oleanders reach 20 feet high (6m). Still, Oleanders do share a number of features, such as their tendency to produce many branches bearing narrow leaves along the stems. Also, the flowers -- unless they're "double-blossomed" types -- look like those below:
If you cut a blossom down its center you see other distinctive features, as shown below:
The white, columnar item at the bottom, center is the ovary, or future fruit. Notice the "tepee" covering the ovary. The tepee consists of five fused stamens. The erect, fuzzy items in the picture's top center are appendages arising atop the stamens' anthers. Maybe they help pollinators hold on as they do their work.
Oleanders are native to the Mediterranean region. All parts of the plant are poisonous, but they are very bitter and one would have to eat a lot to die.