Spiranthes cernua aka Common Ladies' Tresses

Spiranthes cernua is an orchid called nodding lady's tresses. It is a perennial, living for more than two years. Its native range spans eastern Canada. It also spans the central and eastern United States. It grows in swamps, bogs, meadows, and wet roadside sites. It suits a temperate climate and damp garden sites. Growth is slow. Rhizomes, or underground stems, spread to form colonies where conditions suit it.

Flower spikes stand about 0.75–1.5 feet [0.23–0.46 metres] tall. Some reach 2 feet [0.61 metres]. Plants spread about 0.75–1 foot [0.23–0.30 metres] wide. The green stems stand upright and are smooth and round. Three or four narrow leaves form a basal rosette at ground level. These lance-shaped leaves can reach 1 foot [0.30 metres] long. Their edges are smooth, and they often die before bloom. Strong plants may keep one or two small lower stem leaves.

The small white flowers bloom in September and October. The wider bloom season runs from late summer into fall. Flowers may last until the first frost. Each flower measures about one-third inch. It has a strong scent. The blooms nod downward, with a hood above a lower lip. Each flower has three sepals and three petals. Dense rows of blooms twist around the upper flower stem. Uneven cell growth makes the stem twist. Bees visit the flowers. Fertilized blooms then form capsules that hold tiny seeds. Wind carries the seeds away.

Grow this orchid in part shade and moist, boggy, acid soil. It accepts clay, loam, sand, and shallow rocky soils. It also copes with wet ground and spells of standing water. Its listed hardiness range covers USDA zones 5–9. These needs suit pond edges and damp native gardens. Its late blooms add interest to moist meadow plantings. The scent and spiral flower spikes give it its main garden appeal.

You can raise more plants by division, splitting a plant. Growing it from seed is hard. The roots need the right fungal partner. This endomycorrhizal link helps the plant grow and develop as it should. Moving established plants is easier than with many other orchids. Care needs are moderate. The sources report no serious pest or disease problems. They do not establish whether any parts are safe to eat. Nor do they assess toxicity for people or pets.