Wow! From this fabulous group of mostly US natives, comes a species that is virtually unknown in cultivation, despite being highly prized by the late Thomas Jefferson. Each 4' wide clump is smothered during midsummer with thousands of narrow tubed, 4" long, lightly fragrant flowers of white with a pink tinge toward the tip. In midsummer, M. longiflora is visible from quite a distance. I guess this nocturnal flowering species doesn't quite qualify as a 4 o'clock, so maybe we should call it a 7 o'clock... although the flowers are still open the following morning.