1	"Labellum without calli, entire; lateral sepals spreading, not recurved in mature flowers"	2
1	"Labellum with calli, entire, undulate or incised; lateral sepals recurved or revolute in mature flowers"	3
2	"Flowers usually yellowish; labellum ovate to elliptic, lamina flat; lateral sepals very blunt, not hidden by labellum"	"Microtis atrata"
2	"Flowers green; labellum lamina more or less circular and concave; lateral sepals recurved, acute, hidden by labellum"	"Microtis orbicularis"
3	"Labellum more or less triangular, apex obtuse or acute, lamina with only basal calli (sometimes with a minute papillose cushion in apical half)"	"Microtis parviflora"
3	"Labellum more or less oblong, apex truncate, notched or bilobed, lamina with apical or subapical callus"	4
4	"Flowers distant; petals spreading below dorsal sepal; labellum two-thirds to as long as ovary"	"Microtis rara"
4	"Flowers not distant; petals partly hidden within dorsal sepal; labellum less than half as long as ovary"	5
5	"Labellum pendulous, strongly bilobed (with hook-like, decurved point between lobes); dorsal sepal with acute, upturned apex"	"Microtis arenaria"
5	"Labellum pressed against ovary, shallowly notched; dorsal sepal with obtuse apex"	"Microtis unifolia"