Cypripedioideae

Cypripedioideae is a subfamily of the orchid family (Orchidaceae) known commonly as lady's slipper orchids. The group comprises three widely accepted genera: Cypripedium, Paphiopedilum, and Phragmipedium. In some classifications, Selenipedium is placed within Cypripedioideae as a fourth genus, though its placement varies by taxonomic system.

A defining feature of Cypripedioideae is the distinctive lip, or labellum, which is shaped like a slipper or pouch. The pouch traps pollinators such as bees and wasps, guiding them to pass by the reproductive structures and deposit or collect pollen as they escape. This specialized pollination mechanism distinguishes slipper orchids from other orchid groups. The plants typically have broad, often pleated leaves and a range of growth forms from terrestrial to lithophytic or epiphytic, depending on the genus.

Distribution and habitat vary by genus. Cypripedium species are primarily temperate, occurring in the Northern Hemisphere; Paphiopedilum is largely tropical or subtropical in Asia; Phragmipedium is native to the Americas, with several species in tropical montane habitats. Selenipedium, when treated as part of the subfamily, also occurs in the Americas. They occupy forest floors, rocky slopes, and other shaded environments, often favoring humus-rich substrates.

Ecology and conservation: Seed germination depends on mycorrhizal fungi during early life stages. Many species are threatened by habitat loss, over-collection, and climate change, leading to protective status under national laws and international agreements (including CITES in many cases). Conservation efforts emphasize habitat preservation and responsible cultivation.