Physostegia purpurea aka Eastern False Dragonhead

Physostegia purpurea belongs to the mint family, Lamiaceae. It is a perennial, which means it lives for years. Common names include eastern false dragonhead and savannah obedient-plant. It comes from the southeastern United States. Its range covers North Carolina, South Carolina, Georgia, and Florida. In North Carolina, it grows in the coastal plain. It grows in wet savannas and where they meet swamps. It also grows in ditches beside former pine lands.

Plants grow 2–3.5 feet [0.61–1.07 metres] tall. The green stems are square in cross section. They have no scent. Green leaves grow in opposite pairs along each stem. Each leaf is simple, not split into leaflets. The leaves are lanceolate, shaped like a lance head. They have small teeth along their edges but no hairs. Leaves are 0.25–0.5 feet [0.08–0.15 metres] long. They are 0.08–0.25 feet [0.03–0.08 metres] wide. The long, narrow leaves contrast with the pink-purple blooms.

Flowers open from May through August, through much of summer. They grow in racemes, with blooms along a central stalk. They do not grow as single blooms. Each flower has five lobes that form two lips. Each bloom holds four stamens. Bees, other pollinators, and hummingbirds visit the flowers. The plant draws songbirds too. Olive-brown fruit forms from June through September. This fruit is a schizocarp, which splits into parts. Flowers and fruit can thus share part of the season. The long bloom season gives gardens months of flowers.

Grow this plant in full sun. Give it six or more hours of direct light each day. It suits moist, sandy soil that drains well. It also copes with wet soil and floods at times. In the wild, it grows in sand with little or no humus. NC State lists USDA hardiness zones 8a through 11b. Though it grows near the coast, it cannot cope with salt. Keep it away from salt in coastal gardens.

This native plant suits rain gardens and water gardens. Use it by ponds or in beds beside streams. It also suits native plantings and gardens that draw pollinators. Bogs, swamps, and wet savannas meet its stated needs. Its flowers give wildlife nectar and pollen. The supplied sources give no pest or disease details for this species. They do not establish edible uses or toxicity either.