The genus Gynura is an unlikely member of the Asteraceae family of plants. Gynura are warm-climate plants with attractive foliage. The first species I encountered, sometimes referred to as Okinawa spinach, I know as Gynura crepinoides, though I suspect this name is not correct. It is a sprawling groundcover which hails from Indonesia, with elongated, deep green leaves with purple undersides, which are very pleasing. It can cover quite a wide area and seems best in part-shade. It is frost tender. Tip pruning will help keep it more compact, as will giving it a hard haircut in late winter.
It has a weird orange flower like an emaciated dandelion (which, of course, is also a member of the Asteraceae family), not at all pretty and also rather smelly! I remove these, and they probably won't appear if you keep trimming the plant regularly to keep it shapely. I enjoy growing it beneath a form of Justicia carnea with purple undersides to its large foliage, and nearby dark-leaved Tradescantia pallida, to echo its purple tints. The plant is supposedly edible, but I have yet to try it.
Note:This plant is now known as Crassocephalum crepidioides.