Verbena hastata L.
Blue Vervain, Blue Verbena, Swamp Vervain, Simpler’s Joy, Common Verbena
Blue vervain is native to eastern North America. They have a preference for moist ground. The first time I saw them, I thought I had caught them just beginning to bloom, since only a small portion of each flower stalk was in bloom. But that’s how they operate. Each flower stalk looks a little like a fuse, with a burning blue spark hissing along its length.
Identification: Plants are 24-60" (60-152 cm) high, with stiff red or green stems that are square in cross-section and sometimes coated with fine white hairs. They have opposite leaves up to 6" (15 cm) × 1" (2.5 cm), serrated with teeth that vary in size. On the upper half of the plant, the stem branches into several stiff spikes up to 5" (12 cm) long, with attractive blue-purple flowers. Individual flowers are less than ¼" (6.3 mm) around, with five petals. Blooming begins at the bottom of each spike, moving upward as a ring of flowers. Flowers appear from July to September. Fruits are four long, narrow nutlets that separate.
Verbena hastata on Missouriplants.com
Verbena hastata at Illinois Wildflowers
Verbena hastata at the University of Wisconsin's Robert W. Freckmann Herbarium
Verbena hastata at the Lady Bird Johnson Wildflower Center
Verbena hastata on the USDA Plants Database
Verbena hastata at the Missouri Botanical Garden
Verbena hastata from the Jepson Manual
Verbena hastata description by Thomas H. Kent, last updated 24 Jul 2017.
Range: Zones 3-8: