White Mignonette Orchid - Microtis alba

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White Mignonette Orchid - Microtis alba

A handsome tall onion orchid to 600 mm (2'), but although called the White Mignonette Orchid, it can also have cream or even green flowers. It usually only blooms after summer bushfires and has been noted in small scattered groups, growing in low-lying heath and on sandy rises around saltlakes. I have seen them in flower during October/November, but they are known to flower through to January.

The labellum is quite distinctive, being long and very broad (almost triangular) at the extremity, where it divides into two wavy edged lobes. Most of the labellum has a wide wavy frill that can be seen with the eye, making it quite different from other local Microtis species, so with a close look even the green flowered varieties should be easy to identify.

Common Mignonette Orchid - Microtis media subsp. media

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Common Mignonette Orchid - Microtis media subsp. media

A highly variable species with several subspecies. This one varies greatly in height from 200 mm (8") to over 600 mm (2') and like its name suggests is very common by occurring in most soil and habitat types, and from very sheltered to quite exposed locations. It is certainly more plentiful after a bushfire but still easily found without one.

This species can be distinguished from other onion orchids by the slender labellum that is usually bilobed at the end. The labellum is frilled but not strongly so, although may be slightly wavy with lateral lobes small to non-existent. Nevertheless, this orchid is still highly variable and entire colonies can be cloned from a single individual that may be an unusual form, simply by reproducing itself from root tubers.

Although largely dependent on the degree of shelter and soil moisture, the Common Mignonette Orchid can be found in bloom anytime from September to January.

Dark Mignonette Orchid - Microtis orbicularis

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Dark Mignonette Orchid - Microtis orbicularis

A common widespread onion orchid, usually in scattered small colonies and growing to 350 mm (1' 2") but often smaller. It resembles the Sweet Mignonette Orchid, Microtis brownii, in that it has the flowers well spaced on the stem, however this orchid blooms much earlier and is usually finished before the other comes into flower.

The main distinguishing feature with this species is the round disk-like labellum and is the only Microtis to have one of this structure. So a very easy one to identify. It normally grows in low-lying areas around ephemeral swamps and does not need a fire to make it bloom. It has a long flowering period and can be found at anytime from August to November.

Sweet Mignonette Orchid - Microtis brownii

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Sweet Mignonette Orchid - Microtis brownii

Growing from 200 mm (8") to 600 mm (2') it is highly variable in size, but still easily recognisable by the spaced flowers along the stem. Plus more importantly by the large labellum that is pressed against the prominently stalked ovary.

This onion orchid is more common after a summer bushfires, but can still be found in low-lying areas without this influence. It is a widespread orchid, however where I am to the east of Esperance, I have not found it in large colonies, but only in scattered small groups. Flowering time is recorded from November to January, although here it seems to be earlier, being from October to December (possibly due to a more open and harsher environment than the SW of the State where it also occurs).

Swamp Mignonette Orchid - Microtis atrata

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Swamp Mignonette Orchid - Microtis atrata

Probably the smallest of the onion orchids, usually growing from 40-80 mm (2"-3"), but what they lose in size they more than make up for in numbers. They like the winter-wet zones on the edges of swamps and after a summer bushfire, can number in their millions, literally carpeting the ground. Being so small they are quickly smothered by other vegetation so these mass displays will only occur immediately after the fire and before other vegetation can dominate. But not to worry, as they can usually still be found in small scattered colonies in natural clearings for a number of years.

They will flower from late August through to November, and as they mature take on a yellowish appearance, particularly in drying conditions. This coloration makes them very noticeable and along with their size and numbers, very easy to recognise.