It forms diffuse colonies with tiny, inconspicuous flowers and small, more or less round leaves and grows mainly in mossy places in myrtle beech forest.

Townsonia viridis is a terrestrial, perennial, deciduous, sympodial herbs which grows in small groups with the tubers connected by a fleshy root.

Both flowering and non-flowering plants have an erect, very thin leaf emerging at ground level.

The labellum is a broad egg shape, 5–6 mm (0.20–0.24 in) long and wide, folded lengthwise with the tip turned downwards.

[2] The beech orchid was first formally described in 1906 by Joseph Dalton Hooker who gave it the name Acianthus viridis and published the description in Flora Antarctica.