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Tallong Midge Orchid

The Survivors
by Greg Stone

Fire in the Bush
by Greg Stone

More Road Kill
by Phil Mosies

Injured Native Wildlife
Emergency Management

Goldrush Grog
by Phil Mosies

Spring Purples and Pinks
by Greg Stone

Road Kill Recipes
by Phil Mosies

History
Penrose General Store

The Spotted Gums
by Greg Stone

Winter Fires
in Tallong





What is....
Genoplesium plumosum?

The Tallong Midge OrchidIt's the Tallong Midge Orchid of course!

One of the rarest plants in Australia and listed as an endangered species, Genoplesium plumosum, more commonly known as the Tallong Midge Orchid, only occurs in a few small pockets in and around Tallong, and no where else on the planet.

The image at right, is displayed with the kind permission of Paul Holmes of Tallong.

Habitat
The known locations of the species are characterised by having very shallow soils overlying flat to gently sloping sheets of sandstone. The surrounding vegetation is low scrub/heath dominated by Violet kunzea (Kunzea parvifolia), Common Fringe-myrtle (Calytrix tetragona) and Eggs and Bacon (Dillwynia sp.) to name a few, and native grasses such as kangaroo and wallaby grass. Five other autumn flowering Midge Orchids, with which the Tallong Midge Orchid could be confused, also grow at the same sites, along with several other orchid species. At all sites the habitat is surrounded by Brittle Gum (Eucalyptus mannifera) and Scribbly Gum (E. rossii) low woodland.

Description
The species is almost impossible to detect except when flowering. The flowers occur on a single stem up to 20cm tall with 1-8 smalll flowers, about 5cm across, clustered at the top of the stem. The flowers are green with purple stripes and a reddish purple tongue. The almost leafless stem is very thin and about 10-15 cm long, superficially like a blade of grass.

Ecology
Life Cycle
Very little is known about the biology of Tallong Midge Orchid. Midge orchids in general die back after flowering and fruiting and exist only as a dormant tuber for much of the year. During either spring or autumn (depending on the species), they will produce a single erect stem. The flower spike emerges through the leaf near the apex of the stem. Midge orchids don't necessarily flower every year, often skipping years when rainfall hasn't occured prior to the flowering period.

As far as the Tallong Midge goes, initial observations suggested the species flowers 4-6 weeks following good autumn rains. However, this flowering behaviour appears to vary. In autumn 2000, even after plentiful autumn rains, no flowering specimens appeared, despite several searches at sites where the species was observed flowering the previous year.

In contrast, despite average rainfall in late summer/ early autumn 2001, numerous plants flowered at most previously known sites. Although successful flowering and reproduction is likely to be dependent on favourable weather conditions, the specific factors that influence flowering behaviour is poorly understood.

Pollination biology of the Tallong Midge Orchid isn't known, but most Midge orchids are said to be pollinated by vinegar flies, although some are self-pollinating (Jones 1988).

As far as damage by fires goes, it's thought that little impact on the species would result, unless they were extremely hot. The only exception might be if fires occured whilst the plant was flowering or fruiting.

Ability of Species to Survive
There are no immediate threats to most of the populations, and providing other potential threats can be controlled with the cooperation of landowners and Mulwaree Shire Council, there appears to be no reason why the Tallong Midge Orchid can't be maintained in the wild in the long term.

Since we had good rains in early February, and autumn is now upon us, it's nearing the time when our Tallong Midge Orchid should make its annual appearance ...if all is well. So find the magnifying glass and some kids (they're closer to the ground) and start combing the landscape ...see if you can discover some new colonies. Good luck!

For further information, or if you *think* you've discovered a new colony, contact the National Parks and Wildlife Service in Queanbeyan on 02 6298 9700


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