A UK seed company, "Thompson & Morgan's"...offered seed gathered from Dianthus planted in a 17th Century garden estate and advertised as a perennial, pink with blue stems. (At that time, dianthus was not offered as a perennial nor as seed.) It was the first plant I'd ever started from seed...about 15 years ago. I still have them...everywhere. They have a powdery floral scent that wafts all day long June to July.