(Verbena bonariensis) Introduced in the early 1700s to US gardens, Purple Top Verbena is highly attractive to butterflies and a dependable bloomer from mid-summer through first frost. The foliage is so airy and the flowers so intensely purple-pink that it almost looks like the blooms are floating. Strong stems are perfect for pretty cut arrangements. Can be hard to find. 3-4 feet. Full sun. Re-seeding annual. 50+ seeds.