Pink perennial from rhizome
Thank you for attaching the image. Your mystery plant is one of various four o’clocks, sometimes called Marvel of Peru, and has the botanic name Mirabilis jalapa. It’s one of the old-fashioned plants people recall seeing in their grandmother’s garden.
Four o'clocks are useful perennials for reliable seasonal color in your region. Colors include the pink as in your image, also purples, white, striped, and yellow. It grows from a tuber and thrives with minimum attention with the bonus of fragrant flowers.See http://aggie-horticulture.tamu.edu/newsletters/hortupdate/2009/aug09/FourClock.html