Spiranthes incurva (Jenn.) M.C. Pace

Sphinx Ladies' Tresses

Facts About

Accepted Synonym: Ibidium incurvum

Spiranthes incurva, the Sphinx Ladies' Tresses, is a recently described species formerly within the S. cernua complex. It produces 1-5 basal leaves which are held upright but usually wither before the plant flowers. The white to pale ivory flowers form a tightly coiled spiral along the spike in the autumn with lateral sepals that sweep upwards. The raised nectar glands at the base of the smooth labellum curve inwards and are a key feature to distinguish this orchid from S. magnicamporum. This orchid grows in a variety of open habitats, such as fens, meadows, and lake edges, as well as along roadsides.

The conservation status of Spiranthes incurva has not been widely reported and may currently be under review in several areas where it occurs.


Although specific pollinators for this orchid have not been identified, most Spiranthes attract bumble bees that move upward on the inflorescence in search of nectar. Older flowers at the base of the stalk have more nectar, which makes them an efficient first stop for the foraging bumble bees.

Ecosystem Type

Bogs, dunes, fens, grassland, meadows, prairie, stream bank


Leaf arrangement:
Number of leaves on stem:
Form of the labellum:
the labellum is not pouch-like
Labellum outline:
the labellum is simple
Main color of labellum:
Nectar spur:
Inflorescence type:
the inflorescence is a spike
Labellum characteristics:
the labellum is simple
Labellum length:
7.4–9.9 mm
Sepal length:
8.6–10.9 mm
Plant height:
Up to 40 cm
Show All Characteristics

Native to North America


North American Conservation Status & Distribution

Conservation Status

Select a location to view conservation status:

Conservation and Wetland Status
Global Rank N/A
US Status N/A
Canadian Status N/A

North America Distribution

Adapted from USDA data