Thelys

Thelys is a genus of plants in the family Orchidaceae, commonly known as the lady's slippers. These orchids are characterized by their distinctive, slipper-shaped lip, which serves to trap insects that then pollinate the flower. The genus is found in temperate regions of the Northern Hemisphere, with species distributed across North America, Europe, and Asia.

There are a limited number of species within the Thelys genus, with notable examples including Cypripedium calceolus (yellow lady's slipper) and Cypripedium reginae (showy lady's slipper). These plants typically grow in woodland or meadow environments, preferring moist, well-drained soil. Their cultivation is often challenging due to specific ecological requirements, making them a prized find for orchid enthusiasts.

Thelys species are perennial herbaceous plants. They produce a single flower or a small cluster of flowers, each featuring two lateral petals, a large dorsal sepal, and the characteristic inflated, pouch-like labellum. Reproduction in Thelys is primarily achieved through pollination by specific insect species, which are lured into the slipper by visual cues and scent. Once inside, the insect must escape through a narrow opening, brushing against the stigma and anthers in the process, thus facilitating pollination. Due to their slow growth and specialized habitat needs, many Thelys species are considered rare or endangered in certain regions.