Description: Spikes of purple flowers with fuzzy, gray-green leaves.
Growth Habit: Upright, clump-forming perennial. 2ft height
Sun/Shade: Full sun.
Water Needs: Low; drought-tolerant.
Soil Preferences: Well-drained, sandy or loamy soil.
Benefits: Attracts pollinators and adds vertical interest. Great for prairie plantings.
 
From Prairie Moon Nursery:
Hoary Vervain's floral spikes bloom from the bottom up. Livestock will not eat Verbena so it may be thought of as "weedy" by some who observe it in a pasture setting. In a natural prairie it is not aggressive.  In fact, it is a rather short-lived perennial that will not compete well with more aggressive vegetation.  It self-seeds readily and is very easy to germinate, so it is a common component of many drier prairie seed mixes.  The seeds are a staple for many small mammals and birds that depend on this widely-distributed plant.  The gray-green leaves are fuzzy on both sides and are the larval host for the Common Buckeye Butterfly.

Also simply called Hoary Verbena, this Vervain has a long bloom time; the blue-purple flower spikes will persist for 4-6 weeks, usually spanning July and August.