I was thinking about night (and evening) flowers today. A number of plants have flowers that open up in the evening, or are most fragrant in the evening. Usually, they're pollinated by night-flying moths or beetles or in warm tropical regions, bats.
A common denominator is fragrance; moths have a keen sense of smell through their feathery antennae, so flowers that open in the evening often have agreeable scents.
Think about evening primrose, magnolias, four-a-clocks, gardenias, moonflowers, tuberoses, fringetree, and a host of others. They all are fragrant, and luminous in the evening. A lovely book, The Evening Garden: Flowers and Fragrance from Dusk till Dawn by Peter Loewer is a great reference. It was republished by Timber Press in 2002, so copies are still available. It's an excellent guide to creating an evening garden.