What is this flower?

[frdnicholas]

We've been calling it oleander but I don't think that's what it is.

 

[Marck]

This is Mexican Bluebell (Ruellia simplex), a member of the Acanthus family (Acanthaceae). It is native to warm areas of the New World, from the southeastern United States to South America. It often referred to by the synonym, R. brittoniana. Other common names include Mexican Petunia or Wild Petunia, but it is only distantly related to the genus Petunia, in the Nightshade Family (Solanaceae). Purple, pink, and white-flowered forms are available.

 

[frdnicholas]

Thanks. It is certainly prolific!

 

[wkevinc]

This is Mexican Bluebell (Ruellia simplex), a member of the Acanthus family (Acanthaceae). It is native to warm areas of the New World, from the southeastern United States to South America. It often referred to by the synonym, R. brittoniana. Other common names include Mexican Petunia or Wild Petunia, but it is only distantly related to the genus Petunia, in the Nightshade Family (Solanaceae). Purple, pink, and white-flowered forms are available.

God I love the Internet. Thank you for your perfectly definitive answer to this question. What else could possibly be said?