sweet onion-orchid

Microtis oblonga is a terrestrial, perennial, deciduous, herb with an underground tuber and a single erect, smooth, tubular leaf 200–600 mm (8–20 in) long and 6–8 mm (0.2–0.3 in) wide. Between ten and fifty bright green, sweetly scented flowers are arranged along a flowering stem 400–900 mm (20–40 in) tall. The flowers are 5–6 mm (0.20–0.24 in) long and 2–3 mm (0.08–0.1 in) wide. The dorsal sepal is more or less erect, about 3 mm (0.1 in) long and wide. The lateral sepals are 3 mm (0.1 in) long, about 1 mm (0.04 in) wide with their tips rolled under. The petals are 2–2.5 mm (0.08–0.1 in) long, about 1 mm (0.04 in) wide and usually curve forwards. The labellum is oblong, 3–3.5 mm (0.12–0.14 in) long, 1.5–2 mm (0.06–0.08 in) wide with irregular edges and turns downward towards the ovary. There is a raised, dark green callus in the centre of the labellum. Flowering occurs from October to February.

The sweet onion orchid grows between grasses and shrubs in open forest from Gympie in Queensland south through New South Wales, Victoria and Tasmania and west to south-eastern South Australia.