Spiranthes

Spiranthes magnicamporum Arkansas

Spiranthes spiralis Chancy 30 08 2014 03

Spiranthes romanzoffiana 2

Spiranthes, commonly known as ladies' tresses, is a genus of orchids that encompasses a variety of species known for their distinctive spiral arrangement of flowers along the floral axis. This genus is widespread, with species found in diverse habitats across the Americas, Asia, and Australia. The name Spiranthes is derived from the Greek words speira (spiral) and anthos (flower), reflecting the characteristic spiraled flower spikes for which these orchids are known.

Description

Spiranthes species are perennial herbs with tuberous roots or rootstocks. They are characterized by their rosettes of basal leaves, which may be present or absent at the time of flowering. The inflorescence is a spike, notable for its spirally arranged flowers that give the genus its name. Flowers are typically small, white, and fragrant, with a three-lobed lip and a hood formed by the fusion of the sepals and petals. The flowering period varies among species, occurring from late summer to fall in many temperate regions.

Ecology

Spiranthes species are found in a variety of habitats, including meadows, prairies, woodlands, and wetlands. They are adapted to a range of soil types, from moist, well-drained soils to drier, sandy soils. Many species are terrestrial, but some are semi-aquatic, thriving in wetland areas. Pollination is primarily by bees and other insects, attracted by the flowers' fragrance and nectar. Some species of Spiranthes are known for their late flowering period, which extends into the fall when few other flowers are in bloom, providing an important nectar source for pollinators preparing for migration or hibernation.

Conservation

The conservation status of Spiranthes species varies widely. Some species are common and widespread, while others are rare and endangered, facing threats from habitat loss, degradation, and the impacts of climate change. Conservation efforts for rare and endangered Spiranthes species include habitat protection, management, and restoration, as well as ex-situ conservation measures such as seed banking and cultivation in botanical gardens.

Species

There are over 30 species of Spiranthes, including:

• Spiranthes australis – found in Australia
• Spiranthes cernua – nodding ladies' tresses, widespread in North America
• Spiranthes sinensis – widespread in Asia
• Spiranthes spiralis – European ladies' tresses, found in Europe and North Africa

Cultivation

Spiranthes orchids are cultivated by orchid enthusiasts for their unique spiraled inflorescences and fragrant flowers. They require well-drained soil and can be grown in pots or in the ground in suitable climates. Some species prefer full sun, while others thrive in partial shade. Watering needs vary among species, with some requiring consistently moist soil and others preferring drier conditions. Overwatering can lead to root rot, so proper drainage is essential. Fertilization with a balanced orchid fertilizer can promote healthy growth and flowering.

Gallery

Note: As per the instructions, no placeholder images are included.

See also

• Orchidaceae
• Pollination
• Conservation biology