Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Wednesday, August 17, 2011

Illawarra Bird Orchids start to flower on Budderoo Fire Trail

I have posted about the Bird Orchids of Budderoo Plateau in previous years.
I cannot help it.

They are so extraordinary, and so localised that I always feel a glow of satisfaction when I find them.
This year, they have started to flower today, 17 August. I have found them flowering as early as 19 July in 2008, and yet they have been known to flower as late as 23 September.

This plant is known also by the name Illawarra Bird Orchid -  a reference to the "open-mouthed" posture of a baby bird, begging for food.

I have been watching these plants for about 5 weeks, firstly as leaves, then as leaves with small buds, then leaves with large upright buds, and today flowers just opening, despite the light rain which was falling. Situation normal on the Budderoo Plateau. These plants grow in shallow soil over a sandstone rock shelf. They flower in late winter, and early spring, when the shallow soil is frequently wet. This heathland on shallow soil is a harsh environment, subject to extreme drying out over summer. These plants become totally dormant at that stage - they lose their leaves and hide under the soil. A good survival strategy.

I am referring to this plant by the name Simpliglottis chlorantha, but PlantNET obstinately refuses to recognise that name. So, when I refer to the illustration from their site, I use the name which they use, Chiloglottis chlorantha.

Note the extraordinary large calli 
or osmophores (scent-producing glands)
on the broad labellum (on left of image).
Illustration from PlantNET - "Chiloglottis chlorantha"

Simpliglottis chlorantha in situ under heath plants
These plants grow in and under the low heath plants 
and "Eggs and Bacon" Pea flowers
which thrive on the shallow moist, peaty soil over the rock shelves of the area.

The dominant heath plant (in flower at the moment) 
on Budderoo Plateau
The genus name "Leucopogon" refers to "white bearded".
This plant is in the family Ericaceae, known as "heath plants"
Click to enlarge the image, to see the bearded flowers.
Leucopogon microphyllus var microphyllus
 One of the upright Eggs and Bacon Pea flowers 
which thrive on the shallow sandstone soil.
Dillwynia sp. possibly the Barren Grounds species (from nearby)
 The flower here is seen from the side. 
The "lateral sepals" protrude out in front of the flower,
then curve downwards at their tips.
Illawarra Bird Orchid - Simpliglottis chlorantha - earns its green name (chlorantha)
This is a fresh flower, and so the labellum is held quite close 
to the column.
The large pollen grains (pollinia) are just visible
held above the labellum.
Note the green and red glands (calli) on the labellum
These Orchids have two fresh green leaves flat on the ground.
The leaves are often partially covered by leaf litter.
Illawarra Bird Orchid has a red throat under the labellum.

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