Thursday, 30 August 2007

#27 Winter orchids

Before the official end of winter I'd like to show off some of the Hunter Valley's delicate and pretty Greenhood orchids. At a casual glance, ground orchids often go unnoticed amongst grasses and leaf litter, but they are well worth searching out.

The twisted labellum of the Blunt Greenhood

Last week I posted a brief outline of the biology of greenhoods, along with some pictures of the delightful Nodding Greenhood, Pterostylis nutans. I've found another four species in the mid and lower Hunter.

Blunt Greenhood, Pterostylis curta, is a charming flower with a twisted labellum (tongue), somewhat resembling a cheeky cartoon character. This twisted labellum is a distinctive identifying feature. A single stem up to 30cm tall emerges from a basal rosette of 3 to 6 dark green ovate stalked leaves, and bears a single flower. The flower is surprising large, up to 3.5cm height.

The flowering season of Pt. curta is from August to October, and it has been recorded in all eastern states of Australia, as well as South Australia. It can form extensive colonies, and I have seen it growing in moss over rock, moist sheltered areas, grassy woodland and leaf litter.

My Hunter Valley sightings in August of 2007 include Werakata National Park, Watagans National Park, Broke/Wollembi and Hunter Region Botanic Gardens. More information on Pterostylis curta is available at PlantNET.

A rear view of Pterostylis curta, Blunt Greenhood

Trim Greenhood, Taurantha concinna, which has recently had a name change from Pterostylis concinna, is another greenhood with a distinctive labellum, making identification a little easier. The apex of the redddish-brown labellum is notched, forming a 'fork'.

The plant is variable in height, depending on conditions, and I have seen it up to about 20cm high. It has long erect lateral sepals. Whilst the flower is predominently green and white, there are brown tints to the lateral (side) sepals and sinus (V-shape formed at the front of the flower by the lateral sepals). More information on Taurantha concinna at PlantNET.

I have observed Taurantha concinna, Trim Greenhood, growing in leaf litter and grassy open woodland at the Hunter Regional Botanic Gardens at Heatherbrae (May, Jun), and Werakata National Park near Cessnock (Jul, Aug).

The distinctive forked labellum of the Trim Greenhood

Long erect lateral sepals of the Trim Greenhood, in this specimen, sweeping inwards to touch.

Maroonhood, Pterostylis pedunculata, diverts from the usual green to display a dark reddish-brown flower. It has a solitary narrow flower atop a stalk up to about 25cm high. The tip of the labellum is just visible through the deep 'V' formed at the front of the flower by the lateral sepals. Lateral sepals spread upwards or backwards into long linear points.

I have seen Maroonhoods growing in dense colonies at Hunter Region Botanic Gardens at Heatherbrae in the Lower Hunter Valley in a shaded moist position amongst leaf litter in August 2007. More information on Pterostylis pedunculata at PlantNET.

A Maroonhood adorned with spider web. Notice the pointed labellum is just visible

Side and rear view of Pterostylis pedunculata

Rosette of dark-green ovate stalked leaves of Maroonhoods

A colony of Pterostylis pedunculata, Maroonhoods

Tall Greenhood, Bunochilus longifolius, was formerly known as Pterostylis longifolia. It has a long scape (or stem) up to 40cm high bearing lanceolate stem-clasping leaves between 3 and 8 cm in length. At some time in its life, this plant also has a ground-hugging rosette of leaves (although I have not seen this on the plants I found).

Several flowers on the single stem open in succession from the bottom to the top of the plant. Flowers are small (12mm high by 7mm wide) and are translucent green with darker green markings. Lateral sepals are narrow and point downwards exposing an extremely touch-sensitive brown and yellow labellum. More information on Bunochilus longifolius (synonym Pterostylis longifolia) at PlantNET.

Left, the irritable labellum of the Tall Greenhood has been triggered by disturbance to flip back against the column. Right, the labellum of another Tall Greenhood plant has reset itself awaiting an insect pollinator.

Tall Greenhoods that I found flowering in grassy open forest at Hunter Region Botanic Gardens in August 2007 were not growing in dense colonies, but in sparse groupings of 2 to 6 plants.

A Tall Greenhood plant showing leaves, fertilised ovaries developed into seed pods (the brown and green swollen growths), with the top-most flower still active.

And I'll finish my list of winter orchids with some Nodding Greenhoods, Pterostylis nutans, that I featured last week. It was such a delightful group that I couldn't resist photographing them.


Esperance Blog said...

Hi Gaye, a nice follow-up from last week. It is always a pleasure to encounter greenhood orchids no matter how common the species.


Gaye from the Hunter said...

I agree, Westy, that it is always a pleasure to find these little plants no matter how often I encounter them.

Prior to this year, I had only found the Nodding Greenhood in the Hunter Valley, so it's been exciting adding others to my list of local plants.

With the warm weather, Caladenias are now flowering.


Denis Wilson said...

Hi Gaye

Nice posting on your Greenhoods. How far are you from Barrington Tops? There are odd species up there, it seems.

Nice to hear your Caladenias are starting up. None here yet, but we saw a few last weekend at the coast (Nowra). I had terrible trouble photographing the bright blue/purple Glossodia major. The flowers are so shiny, they just over-expose - I kept getting flares of light from the flower.

Eventually I found a new (unfaded) flower, growing in shade,a nd was able to get a nice photo or two.

Like you, I have more photos than time to process them, or write about them all.



Lola said...

Hi Gaye,
Your acute powers of observation are a credit to you.
Another great description of orchids accompanied by your usually high quality photography, which is a lovely follow up to your previous blog. Well done!

Gaye from the Hunter said...

hi Denis,

the Barrington Tops is a vast and diverse area. The section that I visit several times a year to walk and observe (primarily) fungi, is an hour and half drive from my home, and is rainforest.

I have found leaves there that could belong to greenhoods. Sometime in September, I hope to visit the Barrington rainforest to look for epiphytic orchids. I usually have my eyes glued to the ground, so no doubt, I've missed some interesting plants in the trees.


Gaye from the Hunter said...

hi Lola,

thank you for your comment, and I'm pleased you've found my blog and are enjoying my nature observations.

I try to update my blog every week or 10 days, so I hope you stay tuned for more.


David Midgley said...

Hi Gaye -

These pictures of native orchids are great! My jealousy is unending. This season in Berowra I've failed to find any greenhoods, though I have photographed a Caladenia and two Glossodia species!

Gaye from the Hunter said...

hi David,

I'm glad you're enjoying my orchid finds.

Photography of these tiny things that bob about on the breeze certainly is tricky and can be extremely frustrating.

Most of my orchid photography is done with a 'point-and-shoot' digital, so you don't need any fancy or expensive equipment. Although I don't like to use flash, I have recently found that flash photography is more likely to give me a clear picture. The best tip I can give you is to take heaps of frames. Sometimes I have taken a couple of dozen (or even several dozen) pictures of a subject, and it is often the last picture that is the best.

If you are having any specific or continued problems with your photography, please feel free to email me via the 'contact' tab on my blog home page, and I will be more than happy to help if I can.

I have only seen one Glossodia species and the two flowers that I found were in very poor condition. I am hoping I can find more. I have found pink, white and blue Caladenia and a couple more Greenhoods that I will feature on my blog shortly.

Have fun with your orchid spotting, and thank you for leaving a comment here. And please know that my offer of photography assistance is genuine (although I am only amateur myself).