Blue Vervain / Verbena hastata Photo: Flickr user Frank Mayfield, licensed under Creative Commons Attribution-Share Alike 2.0 Generic field image of Verbena hastata BLUE VERVAIN at the James Woodworth Prairie Preserve - 2010 was a record weather year; the Chicago area had the wettest spring and warmest summer in 110 years of recorded weather statistics. This species loves water and warmth, so more specimens grew and bloomed 2010 than in any of the 45 years previous.