"Blue vervain is a native wildflower that spreads slowly through rhizomes and self-seeding. It can grow in disturbed sites and is commonly found in moist meadows, thickets, pastures, riversides, marshes, ditches, and river-bottom prairies. In NC it is found in only a few counties of the coastal, Piedmont and mountain areas.

"The plant forms clumps of stiff upright stems with lanced-shaped leaves with toothed margins. The purple flowers occur in a candelabra-shaped panicle and are a high-value nectar plant with a long bloom season. Blooms open bottom to top with only a few open at one time in mid to late summer."  (North Carolina Extension)

Verbena Hastata Botany by Dr. John Hilty

Vervain family (Verbenaceae)

Cultivation:

"The preference is full to partial sunlight, moist conditions, and soil consisting of fertile loam or wet muck. This plant tolerates standing water if it is temporary. This is a good plant to locate near a small river or pond in a sunny location." (Hilty)

Faunal Associations: 

The flowers of Blue Vervain attract many kinds of long-tongued and short-tongued bees, including honey bees, bumblebees, cuckoo bees (Triepeolus spp.), digger bees (Melissodes spp.), Halictid bees, and dagger bees (Calliopsis spp.), including the oligolectic Verbena Bee (Calliopsis verbenae). These bees seek primarily nectar, although some species collect pollen. Other floral visitors include Sphecid wasps, Vespid wasps, Syrphid flies, bee flies (Exoprosopa spp.), thick-headed flies (Physocephala spp.), small butterflies, skippers, and moths (Robertson, 1929). Other insects feed on the leaves and other parts of Blue Vervain and other Verbena spp. Examples of such insects include both adults and larvae of a flea beetle (Longitarsus suspectus), larvae of the Vervain Leaf Midge (Clinodiplosis verbenae), the Verbena Aphid (Macrosiphum verbenae), leaf-eating larvae of the Verbena Moth (Crambodes talidiformis), and larvae of the Verbena Bud Moth (Endothenia hebesana); see Clark et al. (2004), Felt (1917), Thomas (1877), Covell (1984/2005), and Miller (1987). Mammalian herbivores usually avoid eating this plant because of its bitter leaves – an exception is the Cottontail Rabbit, which may eat the foliage of young plants to a limited extent. Also, various songbirds occasionally eat the seeds, including the Cardinal, Swamp Sparrow, Field Sparrow, Song Sparrow, and Slate-Colored Junco (Martin et al., 1951/1961). Experimental studies have shown that these seeds can pass undamaged through the digestive tracts of cattle, therefore they are probably distributed to some extent by these seed-eating birds." (Hilty)

Covers

1. "Verbena hastata Linnaeus, 1753 - blue vervain (Dawes Arboretum, Licking County, Ohio, USA)" By James St. John - Verbena hastata (blue vervain) 1, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=83884210
2. "Verbena hastata Linnaeus, 1753 - blue vervain (Dawes Arboretum, Licking County, Ohio, USA)" By James St. John - Verbena hastata (blue vervain) 4, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=83884214
3. "Verbena hastata BLUE VERVAIN" by gmayfield10 is licensed under CC BY-SA 2.0
   

North Carolina Extension plant description: Verbena Hastata (Blue Verbena, Blue Vervain, Simpler’s Joy, Swamp Verbena, Swamp Vervain) | North Carolina Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/verbena-hastata/. Accessed 2 Feb. 2022.

John Hilty botany, cultivation, and faunal associations: John Hilty, "Blue Vervain", Illinois Wildflowers, the publisher, Copyright 2004-2019. Accessed 2 February 2022

Botanical image showing Verbena leaf base: "Verbena hastata BLUE VERVAIN" by gmayfield10 is licensed under CC BY-SA 2.0