Size and method of spreading:
At maturity, hoary vervain is between 2 to 4 feet tall and 1 ½ to 2 feet wide. It spreads by self-seeding.
Native geographic location and habitat:
Hoary vervain has a native range that includes the majority of the continental United States. C Value: 4.
Pollinators and wildlife:
Hoary vervain is a great choice for attracting ants, bees, beetles, butterflies, flies, hummingbirds, moths, skippers, and wasps. Hoary vervain is valuable to the specialist verbena bee, Calliopsis verbenae. The seeds of hoary vervain are eaten and distributed by a variety of songbirds, including sparrows. Hoary vervain serves as a host for common buckeye larvae.
Leaf description:
The leaves of hoary vervain are up to 4 inches long and 3 inches wide (ovate or obovate) and mostly stalkless or have short, winged stalks (petioles). They are yellowish-green to medium green and have prominent veins. The edges of the leaves are coarsely toothed (serrate margins), and the base of the leaves are rounded while the tips are tapered to a point. Both leaf surfaces are covered with hair (pubescence). This gives the leaves the hoary, or gray-white, look.
Flower description:
Hoary vervain flowers are tiny, bluish-purple, and densely packed onto pencil-like spikes. The spikes are up to 8 inches long and are branched into small, upright groups (panicles). Only a few flowers open at a time, and they mature upward from the bottom. Each flower is up to one-half of an inch in diameter and has a tubular petallike structure (corolla) that divides into five spreading lobes at the top. The top four lobes are rounded, and the bottommost lobe is notched at the tip. Surrounding the base of the corolla is a leaflike, green to purplish-red, tubular structure (calyx) that divides into five sharply pointed, hairy lobes.
Fruit description:
The fruit of hoary vervain is small, brown, dry, four parted, and does not open to release the seeds (schizocarps). The calyx from the flowers remains around the fruit as it matures (persistent calyx).
