Microtis R.Br.

Deciduous, tuberous, terrestrial orchids growing individually or in spreading clonal colonies. Leaf single, thin, onion-like, hollow. Inflorescence a dense spike or spike-like raceme that grows through the hollow leaf and emerges at a weak spot (fistula) on the longitudinal seam of the leaf, usually about halfway along, but variable according to species. Flowers resupinate, small, opening widely, green or white, each flower perched on a swollen, shortly stalked or stalkless ovary. Dorsal sepal free, broader than lateral sepals, concave, hooding the small column. Lateral sepals free, spreading, recurved, coiled or inrolled. Petals small, often partially enclosed within dorsal sepal. Labellum attached firmly by its base to column base. Labellum lamina unlobed, deflexed, tongue-like; margins smooth, crinkly or irregular, often adorned with irregular, marginal clusters of cells (termed excrescences); apex blunt, truncate or often notched, sometimes with 2 distinct lobes. Callus of smooth, dark mounds on labellum base, supplementary glandular cell clusters (termed apical callus in descriptions) often also near apex. Column tiny with a pair of ear-like wings. Pollinia 4, yellow, sectile, attached directly to viscidium or via short hamulus.

These orchids occur in a wide range of moist to wet habitats including depressions, swamps, bogs and seepage sites, but can also be found growing in well-drained soils in heath, forest and grassland, often among grasses and herbs. They can rapidly colonise recently disturbed habitats and some species occur in gardens, lawns and pasture.