Cynanchum species? Here is a link that might be useful: Cynanchum rossicum

What kind of flower is this?

Why don’t you try asking on the Name that Plant forum, where folks who love doing plant ID hang out. You will want to add your general location and if you know it, your USDA growing zone to help limit the possibilities. The green text is a direct link to that forum.

Because some like cestrum and clereodendron are actually hardy in z7 in the US. Wikipedia describes my location as humid subtropical. I can grow some lantana as die back perennials, crinums, sabal palm, etc. It's not like my z7 is Alaska or something ;0 I know it's not a verbena sp, but the foliage is reminscent of verbena and some things in verbena family, some of which are shrubs.