Blue Vervain

Blue vervain is a native, perennial wildflower that grows
from 2 to 5 feet tall. Its hairy, square stems can be green
or red. The toothed, lance shaped leaves progress in pairs
up the stem and are about 6 inches long by 1 inch wide.
Purplish-blue flowers bloom in multiple, showy,
elongated panicles (flowers arranged on a stem) and are
up to 5 inches long. Each bloom is about 1/4 inch across
and conspicuously lobed. Blue vervain blooms in mid to
late summer; approximately 1 1/2 months after blooming
each bloom gives way to four oblong, reddish-brown,
triangular-convex “nutlets.” Blue vervain spreads
through rhizomes, horizontal roots that produce new
plants.
Blue vervain prefers moist conditions and full to partial
sun. It can grow in disturbed sites and is commonly
found in moist meadows, thickets, and pastures, as well as
riversides, marshes, ditches, and river-bottom prairies.