#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.