Microtidium
atratum (Yellow Onion Orchid) is an uncommon species that grows
in swampy places near the north coast.
This species has a single, erect narrow leaf held high on the
flowering stalk (scape). The scape is erect and unbranched and bears
several to many shortly stalked flowers. The flowers are small and
quite inconspicuous, with sepals and petals less than 2 mm long. The
flowers are inverted (with the labellum above the centre of the
flower, and facing downwards).
This species is very similar to
Microtis species and Hydrorchis
orbicularis, and differs from the former in lacking the dark
swellings on the labellum, and from the latter in having a square-ish
labellum. It also differs from Hydrorchis in being distinctly
yellow-green. |