genus of orchids, family Orchidaceae, containing as many as 125 species native to Eurasia and North America. Each plant bears a single flower spike with many flowers and has egg-shaped, lobed, or forked tuberous roots. Most species have several leaves at the base. The petals and sepals often form a helmetlike structure, and the flower lip usually is several lobed. The monkey orchid (O. simia) and the soldier, or military, orchid (O. militaris) are two European species the flowers of which resemble helmeted human figures.

The root of the early purple orchid (O. mascula) and several other species contain a nutritive starch. In southern Europe they are collected and dried to produce a flour that is mixed with sugar, flavourings, and liquid (such as water or milk) to produce a drink called salep. The green-winged orchid (O. morio) is widely distributed throughout Eurasia. Other Eurasian species of Orchis include some known as marsh orchids and others as spotted orchids. The showy orchis (O. spectabilis) is the most well known of the three North American species of Orchis. It has pink or purple flowers and ranges in height from 6 to 20 centimetres (2 to 8 inches).