September 2016 Winning Picture

Spring is here and it was reflected in the variety and large number of entries.  Lorraine Badger and Ros Miller entered Western Australian species – Caladenia x ericksoniae (Prisoner Orchid) and Paracaelana nigrita (Flying Duck Orchid) respectively.  The other six entries were all from South Australia, Diplodium robustum (Common Green Shell Orchid), Caleana major (Flying Duck Orchid) both from Jane Higgs, Greg Sara’s Oligochaetochilus sp (Rufoushood), Judy Sara’s Arachnorchis leptochila (Queen Spider Orchid), Claire Chesson’s Diuris behrii (Cowslip Orchid or Golden Moths) and the outstanding winning picture Pterostylis cucullata by Bevin Scholz.

 1609-sm-bs-pterostylis-cucullata

In many ways, Bevin’s picture of P. cucullata (Leafy Greenhood) is a special picture because it represents some of the conservation work with which NOSSA is involved. For many years NOSSA has worked with the Threatened Plant Action Group (TPAG) to weed the areas in Belair where this species is located and to see such a good show of plants is encouraging.  It is a tribute to all who have contributed with their time and labour.

P. cucullata is rated Vulnerable both in South Australia and Victoria, and Endangered in Tasmania. It is also rated Vulnerable under the EPBC Act (Federal). Nationally it is known from about 110 sites with most of these sites being in Victoria and only a few sites in South Australia with Belair National Park having the largest and most important population for the state.

Historically this species covered an area of 2107 km2 in the Lofty Block region but that has now contracted by 82% to only 366 km2 with few locations. With such a reduced range, recovery plans were developed, both at state and federal level.  The plans examined the risks and threats to the survival of the different populations.

One of the threats to this orchid is fire, including proscribed burns.  Unlike some species such as Pyrorchis nigricans, Leptoceras menziesii or Prasophyllum elatum which flower well after fire, P. cucullata is fire sensitive; populations decline substantially.  There does not seem to be a safe time to burn for this species.  Should a population survive a burn, it would take it many years to recover.

Fire also leaves the population vulnerable to another threat, that of weed invasion.  Unfortunately, it is weedy where this species survives but over the years, a consistent, targeted weeding program has resulted in a declining weed population.  NOSSA and TPAG have appreciated the work and effort of volunteers and gladly welcome anyone else who would like to join. And one of the rewards? A beautiful, sunlit display of flowers as seen in Bevin’s picture.

Reference:

Duncan, M. (2010). National Recovery Plan for the Leafy Greenhood Pterostylis cucullata. Department of Sustainability and Environment, Victoria https://www.environment.gov.au/system/files/resources/14e1ae30-5cf7-4be6-8a35-2c752886c14f/files/pterostylis-cucullata.pdf

Nature Conservation Society of South Australia (2009) DRAFT RESPONSE ON THE BELAIR NATIONAL PARK TRAILS MASTERPLAN: PRELIMINARY ISSUE January 2009  http://www.ncssa.asn.au/images/stories/ncssasubmission_belairnptrails_masterplan_jan09_final.pdf

Quarmby, J.P. (2010) Recovery Plan for Twelve Threatened Orchids in the Lofty Block Region of South Australia 2010. Department of Environment and Natural Resources, South Australia https://www.environment.gov.au/system/files/resources/e362cfd2-a37b-443a-b007-db3a2b7b64dd/files/lofty-block-orchids-recovery-plan.pdf

Pterostylis plumosa: Plumatochilos plumosum

plumatochilos-sp-woodland-sm
Plumatochilos sp Woodland

 

If you are out and about this week, keep an eye out for this attractive and unusual greenhood with its bottle brush labellum and rosette of “pineapple” like leaves.

Commonly known as Woodland Plumed or Bearded Greenhood, or Plumatochilos sp. Woodland Bearded Greenhood.  The reason for the phrase name is because many consider that it is a separate species, in this instance, from Plumatochilos plumosum (syn Pterostylis plumosa).  Originally all of the Bearded Greenhood were considered as one species – Pterostylis barbata but then Leo Cady named Pterostylis plumosa as a separate species.  David Jones in his 2006 tome listed four species, P. barbatum, P plumosum, P. tasmanicum and P. turfosum.

Here in South Australia, Bates lists P. tasmanicum and two with phrase names suggesting that they are distinct from P. plumosum.

Peter Fehre recently posted on the Tasmanian Native Orchids Facebook page some helpful hints differentiating between P. tasmanicum and P. plumosum.  Very similar information is found in Bates South Australia’s Native Orchids.  These differences are:

P. tasmanicum – a short plant: short flower stem (not more than 14 cms), short labellum (to 15mm) , short ovary; short blunted galea (hood) to 25mm.  It prefers damp, sandy areas and swamp margins.

P. plumosumhas length; long flower stem (10 – 30 cm), galea to 40mm with a long tip, long labellum (to 25mm).  It is a plant of the woodlands and forests growing on well drained soil.

The differences between the two phrase named species are more subtle

References:

R J Bates, 2011, South Australia’s Native Orchids DVD, NOSSA

D L Jones , 2006, A Complete Guide to Native Orchids of Australia

Hands On Conservation – Getting into Conservation at the Ground Level

Conservation of orchids takes many forms, one of which is weeding.  NOSSA members often assist the Threaten Plant Action Group in this area.  There are several sites where significant orchids are under threat from invasive weeds; and over the years, through consistent weeding, the weed front has been pushed back allowing the orchids an opportunity to recover and even increase in numbers.  It is an ongoing task but seeing the orchids recover makes it an encouraging task BUT …

This activity is heavily reliant upon volunteers.  And those who regularly volunteer deserve a big thank you from the community.  BUT ….

More helpers are always needed.  If you are interested in seeing the orchids, consider joining one of the weeding activities that are held throughout the year (these are advertised on this website).  Often the weeding activities target a specific weed, so it is great for a beginner who does not have an in-depth knowledge of plants.

montage-weeding
 The orchids are first marked with tags as they can be difficult to see whilst weeding but afterwards they can be clearly seen.

 

CULTURE OF SLOW MULTIPLYING (SM) TERRESTRIALS

Pots of Thelymitra nuda cultivated by Les Nesbitt
Thelymitra nuda

The second fact sheet in Terrestrial Culture notes is about Slow Multiplying Terrestrials.

FLAGBEARER SPECIES: Thelymitra nuda

Diuris, Pterostylis and Thelymitra. They are more expensive because they have to be raised from seed in flasks. SMs are not so easy because there is less room for error. A few have a near zero increase rate and will fade away unless additional plants can be produced to make up for occasional losses from predators and disease.

GROWTH HABIT: Australian ground orchids follow an annual growth cycle comprising 6 – 8 months as growing plants under cool (5 – 20°C max, 0 – 14°C min) moist conditions and 4 – 6 months as dormant tubers in hot dry
(18 – 42°C max, 12 – 30°C min) conditions. The new tuber is produced in winter – spring. Each tuber sends up a shoot to the surface in Autumn and leaves grow rapidly in late Autumn/early Winter as temperatures fall and the rains set in. Pterostylis leaves are usually the first to appear in March/April followed by Diuris and Thelymitra in April/May. Sometime in October/November the leaves go yellow and then brown and dry as the days get longer, hotter and drier in late Spring.

LIGHT/SHADE: Australian terrestrial orchids are easy to grow. In Adelaide they thrive in a shadehouse of 50% shadecloth. Some species prefer heavy shade, others full sunlight, but most will adapt to a wide range of light intensity. Sun loving species (Diuris, Thelymitra & Rufa group Pterostylis) prefer a brighter location for good growth.

If the leaves and stems are weak and limp or if the leaf rosettes are drawn up to the light then the shading is too dense and the amount of light should be increased. The spring flowering species like higher light intensities at flowering time and flowers may have pale colours if placed in heavy shade, even temporarily, when flowers are just starting to open.

In very cold areas an unheated glasshouse may be required for frost protection although light frosts do not worry the majority of species.

AIR MOVEMENT/HUMIDITY: All species like good air movement and will not thrive in a stuffy humid atmosphere especially if temperatures are high.

WATERING: The soil should be kept moist at all times during active growth by watering gently if there is no rain. Hand watering is especially necessary in spring as soil in pots dries out more rapidly than in the garden. Watering must be done slowly so that the mat of needles on the surface of the pot is not disturbed. Slugs and snails love these plants and must be kept under control. Raising the pots off the ground on galvanised steel benching is very effective in controlling these pests.

After the leaves have turned yellow, let the pot dry out completely to dry up the old roots and tubers otherwise they may turn into a soggy mouldy mess and rot may destroy the adjacent new tubers.

POLLINATION/SEEDCOLLECTING: Flowering plants are hand pollinated and the seed collected just before the pods split open and the dust-like seed blows away. The seed is sprinkled on pots of mother plants at Easter or flasked.

REPOTTING: Repot every second year in half new mix. Repotting is normally done between November and January. The best results are obtained if the tubers are repotted in half fresh soil mix each second year. A suitable soil mix is 40% loam, 50% sand and 10% organic matter with a little blood and bone fertiliser added. A 5 mm sieve is a useful tool for separating tubers from soil. Replant the dormant tubers with the tops 20 mm deep. Cover the soil surface with a mulch of sheoak needles, chopped to 20 – 50 mm lengths, to prevent soil erosion & aerate under the leaves.

INCREASING PLANT NUMBERS: The pull-off-the-tuber method can be used with some diuris and Pterostylis species to double plant numbers annually. The pots can be knocked out and the tubers examined in Summer without harm.

SUMMER CARE: Keep the pots shaded and allow the pots to dry out between light waterings until mid-February when they should be set out in their growing positions and watered a little more often. The tubers of some species will rot if kept wet during the dormant period, others will produce plants prematurely which are then attacked by pests such as thrip and red spider and fungal diseases in the warm weather.

FERTILIZING: SMs will benefit from weak applications of folia feed in the early growth stages.

OTHER CULTURE NOTES:

 

NB: IT IS ILLEGAL TO TAKE PLANTS (WHOLE PLANT, FLOWERS, SEEDS AND TUBERS) FROM THE WILD

CULTURE OF FAST MULTIPLYING (FM) TERRESTRIAL ORCHIDS

Recently, NOSSA updated the Terrestrial Culture Fact Sheet.  Instead of one sheet, it was decided to split it into three – Culture of Fast Multiplying Terrestrials, Culture of Slow Multiplying Terrestrials and Culture of Fungi Dependent Terrestrials.  Though much of the growing information is similar, there are some significant differences of which growers need to be aware.  The first of the fact sheets is Culture of Fast Multiplying Terrestrials.

FLAGBEARER SPECIES: Pterostylis curta

Pterostylis curta Labellum and column 92RL
Pterostylis curta (Blunt Greenhood) is rated rare in South Australia.  Ex situ conservation is another dimension to conservation.

Others include Chilogolottis, Corybas, Cyrtostylis, Diplodium, Microtis most Pterostylis and some Diuris. Most FMs are Autumn or Winter flowering. The exceptions are Diuris and Microtis. FM are the most common terrestrial orchids to be seen at meetings and shows. Once seedlings are established they are no longer fungi dependent.

GROWTH HABIT: FMs are the easiest terrestrial’s orchids to grow. They multiply by forming 2 – 5 tubers per plant each year. The annual growth cycle comprises 6 – 8 months as growing plants under cool (5 – 20⁰ C max, 0 – 14⁰ C min) moist conditions and 4 – 6 months as dormant tubers in hot (18 – 42⁰ C max, 12 – 30⁰ C min) dry conditions.  New tubers are produced in winter/spring. FMs are colony types, ie they multiply annually and will spread out over time if planted in the ground. Each tuber sends up a shoot to the surface in autumn and leaves grow rapidly in late autumn/early winter as temperatures fall and the rains set in. FMs mainly flower in Autumn and Winter. Diplodium & Pterostylis leaves are usually the first to appear in March followed by Diuris and Microtis in April, and Corybas in June to July. In October/November the leaves go yellow, then brown and dry as the days get longer, hotter and drier in late spring.

LIGHT/SHADE: In Adelaide, they thrive in a shadehouse of 50% shadecloth. Some species prefer heavy shade, others full sunlight but most will adapt to a wide range of light intensity. Sun loving species (Diuris & Microtis) prefer a brighter location for good growth. Corybas like the shadiest corner.  If the leaves and stems are weak and limp or if the leaf rosettes are drawn up to the light, then the shading is too dense and amount of light should be increased.

In very cold areas an unheated glasshouse may be required for frost protection although light frosts do not worry the majority of species.

AIR MOVEMENT/HUMIDITY: All species like good air movement and will not thrive in a stuffy humid atmosphere especially if temperatures are high.

WATERING: The soil should be kept moist at all times during active growth by watering gently if there is no rain.  Hand watering is especially necessary in spring as soil in pots dries out more rapidly than in the garden. Watering must be done slowly so that the matt of needles on the surface of the pot is not disturbed. Slugs and snails love these plants and must be kept under control. Raising the pots off the ground on galvanised steel benching is very effective in controlling these pests.

After the leaves have turned yellow, let the pot dry out completely to dry up the old roots and tubers otherwise they may turn into a soggy mouldy mess and rot may destroy the adjacent new tubers.

REPOTTING: They grow better if repotted annually otherwise the plants crowd together around the rim of the pot.  Repotting is normally done between November and January. The pots can be knocked out and the tubers examined without harm.  For best results repot the tubers in half fresh soil mix. A suitable soil mix is 40% loam, 50% sand and 10% organic matter with a little blood and bone fertilizer added. (They will also grow in native potting mix.) A 5 mm sieve is a useful tool for separating tubers from soil. Replant the dormant tubers with the tops 20 mm deep. Cover the soil surface with a mulch of chopped sheoak needles (20 – 50 mm lengths). This prevents soil erosion and assists with aeration under the leaves.

SUMMER CARE: Keep the pots shaded and allow the pots to dry out between light waterings until mid-February when they should be set out in their growing positions and watered a little more often. The tubers of some species will rot if kept wet during the dormant period, others will produce plants prematurely which are then attacked by pests such as thrip and red spider mite and fungal diseases in the warm weather.

FERTILIZING: FMs are very hardy and will benefit from weak applications of folia feed in the early growth stages.

OTHER CULTURE NOTES:

NB: IT IS ILLEGAL TO TAKE PLANTS (WHOLE PLANT, FLOWERS, SEEDS AND TUBERS) FROM THE WILD

 

Genes, seasonal conditions or pure chance?

Leo Davis is an orchid hunter.  He is meticulous in his observations and notes details that many of us may miss.  In this article he muses upon the variations that he sees in the field.

You, as I do, must occasionally come upon an orchid or an orchid event that is a little outside normal experience.  When I do, I wonder whether this is a purely chance event or is it caused by recent local environmental factors, or is it due to the genes of the plants.  Or a combination of these?

I’ve been watching a couple of patches of fire orchids (Pyrorchis nigricans) that many of you will be familiar with, one at Knott Hill N.F.R., the other at Monarto C.P., where a few plants flower every year, without the normally required stimulation by fire.  I need to check whether it is the same plants that flower each year.

Pyrorchis nigricans.jpg
Pyrorchis nigricans (Fire or Undertaker Orchid) Photo: Leo Davis

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The tall leek orchid (Prasophyllum elatum) puts up leaves at Scott Creek C.P. every year but does not flower. A fire swept through in early 2014 and most plants flowered in October.  They’ve not flowered since.  But over at Ramsay Way, west of Pt. Vincent, a few plants flower each year without fire.  I assume genes are involved.

Prasophyllum elatum
Prasophyllum elatum (Tall Leek Orchid) Photo: Leo Davis

 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In April 2014 I chanced upon a patch of Adelaide Hills parson’s bands (Eriochilus collinus), along Moore’s Road, at Morialta C.P., in which the majority of plants had three flowers per stem. Was this because of favourable conditions or genes? Over the next two seasons I saw only the occasional double header and mainly single flowered plants. I will continue observations and records.   

 Eriochilus collinus

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In July 2015 I found a dense patch, about 3 m2 in area, of hundreds the common mallee shell orchid (Diplodium dolichochilum), in Ferries-McDonald C.P. As usual less than ten plants were in flower, but two of them were double headers.  I’ll be checking this season and expect this not to be a chance event but one due to genes.

Diplodium dolichochilum
Diplodium dolichochilum syn. Pterostylis dolichochila (Slim Tongued Shell or Common Mallee Shell Orchid) Photo: Leo Davis

 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

On May 27, 2012, Bob Bates led a NOSSA outing to Scott Creek C.P. and as ever, when he leads, we saw and learned a lot.  He showed us a patch of fringed hare-orchids (Leporella fimbriata) that he assured us should not be growing there on that steep rocky site and that the plants would not flower most years.  Unfortunately he was right, as usual.   I could not find plants in 2013 and 2014 and it took three searches in 2015 to find a very few leaves. On May 10 this year, over an area of less than 10 m2, I found perhaps 50 leaves and just seven plants in flower.  Three of these had three flowers and a tiny unopened bud (check the photo) and the others were doubles.  I’ve never seen a triple flowered plant in hundreds I’ve seen at Knott Hill N.F.R.  Are genes in an isolated population at play here?  Given the paucity of flowering at this site, it may take me years to sort this one out.

Leporella fimbriata
Leporella fimbriata (Fringed Hare  or Ballerina Orchid) Photo: Leo Davis

Leo Davis.

 

Gleanings from the Journals #2 – Harold Goldsack (27/6/1908 – 25/4/1989)

 

[Primary source material is the NOSSA Journals. Direct quotes from the Journal in blue and additional information in black.]

Sometimes gleanings take much time and effort to locate but other times there is an abundance of information just waiting to be picked up. This was the case when searching the Journal for information on Harold Goldsack.

Upon the death of Dr R S Rogers, Harold Goldsack became the leading authority of South Australian orchids. To quote Peter Hornsby (1977), NOSSA’s first editor, “Harold is undoubtedly the most experienced of our native orchid botanists and knows more of the history of our orchids than anyone alive.”

Though not a foundational member, Harold was one of NOSSA’s early members, joining at the end of 1977. He was both a grower of epiphytes – winning the Champion epiphyte for 1982 (Dendrobium x gracillimum) and terrestrials – producing the first greenhood hybrid, Pterostylis Cutie (baptistii x cucullata) which was registered on 5th March, 1982. At the meetings he gave talks, plant commentaries and judged the orchids. Outside of the meetings he was active in advancing the cause of Australian orchids. His enthusiasm influenced many people, one person being a young Mark Clements, current Research Scientist, Centre for Australian National Biodiversity Research, CSIRO, Canberra.

It is not surprising than that in 1984 he was made NOSSA’s second life member.

 

Bob Bates wrote an informative biography in Harold’s obituary.

Journal 1989 Volume 13 No 4 May

Vale Harold Goldsack.

It is with sadness that we announce the passing of life member Harold Goldsack on April 25th. Our sympathies to his family.

Harold was born in East Bengal, India on 27th June 1908. He once told how he could remember epiphytic orchids blooming outside the bedroom window of his childhood home.

His family moved to Adelaide in 1916 and he attended Princes College as a boarding student.

He was introduced to South Australian orchids in bushland adjacent his family’s orchard at Coromandel Valley using Rogers “Introduction to the Study of South Australian Orchids” to identify these. Harold in 1924 introduced himself to Dr Rogers and they became good friends. Harold soon began to find orchids that were new to Dr Rogers and this fired his enthusiasm so that he began a serious study of our orchid flora.

One day in 1928 on a visit to Dr Rogers, Harold was shown the very first collection of the underground orchid Rhizanthella gardeneri. This was to be the subject of the last article Harold wrote over 50 years later.

With the passing of Dr Rogers in 1942 Harold became the foremost authority on South Australian orchids corresponding regularly with H M R Rupp, W H Nicholls and A W Dockrill. His extensive collection of pressed orchids was donated to the State Herbarium in 1978.

Harold wrote many articles on orchids his best known being “Common Orchids of South Australia” which appeared in the S Aust Naturalist in June 1944 and was used in “National Parks and Wild Life Reserves” book from 1965-1970. Harold also revised the orchid section of Black’s “Flora S Australia” in 1943.

Besides drawing and photographing the S Aust orchids Harold developed a large personal Orchid Library and cultivated many Australian orchids which he displayed at shows including our NOSSA shows. The first registered Pterostylis hybrid Ptst. Cutie was made by Harold and the name given to the original clone now grown by hundreds of orchid lovers is “Harolds Pride!”

His main interest was to enthuse others to see the beauty and value of our native orchids through his articles and the many illustrated talks he gave to natural history groups.

Harold was a member of the Royal Society of S Australia.

He was a Foundation Member of the Australian Native Orchid Society. (ANOS)

Ever ready for a challenge Harold at age 64 began studying for his Engineering and Surveying Certificate gaining distinctions in Maths, then working on the surveying of the S E Freeway.

Harold Goldsack’s name is commemorated in the South Australian endemic orchid Prasophyllum goldsackii, a fitting tribute to a true orchid lover.

R Bates

53KB Prasaphyllum goldsackii
Prasophyllum goldsackii – Photographer Ken Bayley

Bibliography of Papers by Harold Goldsack

Orchids of Coromandel Valley – SA Naturalist XIV, Nov 1932 PP 12 – 15

Notes on Caladenia Catifolia – R Br SA Naturalist XV, March 1934, pp 59 – 63

National Park of South Australia – Field Naturalists Sect. of Royal Soc of SA 1936, Being Vol XVII, Nos 1 to 4 of SA Naturalist pp 52 – 54 Orchids

Common Orchids of South Australia – SA Naturalist XXII June 1944 PP 1 – 12 with line drawings of 52 species

New Orchid Records for South Australia – SA Naturalist XXII June 1944, p 13

National Park and Reserves – Commissioners of the National Park, Sept 1956 pp 59 – 79 with line drawings of 52 species of Orchids, p 195 Distribution and flowering times of orchids in the National Park and Reserves

SA National Parks and Wild Life Reserves – Commissioners of the National Park and Wild Life Reserves, March 1964, pp 46 – 64 Orchids with line drawings of 52 species, pp 189 – 199. Distribution and Flowering times of Orchids in the National Park and Reserves

Orchids of the National Park and Wild Life Reserves – Reprinted 1965 by Field Naturalists Society, if (sic) SA from “SA National Parks and Wild Life Reserves” with permission of the Commissioners of the National Park and Wild Life Reserves

Blacks’ Flora of South Australia – Revised edition of p1, 1946 Assisted Rev H M R Rupp and W H Nicholls with the revision of the Orchidacea

Pollination of Caladenia deformis R Br – R S Rogers transactions of Royal Society of SA Volume LV Oct 1931 The pollination of Caladenia deformis as observed by H G was written up by Dr R S Rogers in an article for the Royal Society of SA

Rhizanthella gardnerii R S Rogers – The Orchadian p 113 Sept 1979 A note about the discovery of this orchid

Following is the article by Harold Goldsack referred to by Bob Bates in Harold’s obituary. Though he wrote for other publications, this was appears to be the only one in the NOSSA Journals.

Journal 1979 Volume 3 No 8 August

RHIZANTHELLA GARDNERI Rogers                              Harold Goldsack

Corrigin, Shackleton, Goomalling, Munglingup. Western Australia.

A new locality where the subterranean orchid Rhizanthelle gardneri Rogers has been found, as noted by Don Voigt in his letter to Roy Hargreaves to brings with it hope that after 50 years the secret life of the remarkable orchid may be unveiled. It also brings back memories of my first encounter with this plant.

As a young orchid enthusiast I had been collecting for, and writing to, Dr R.S. Rogers of Adelaide, who, at that time, was an extremely busy public personality. To my surprise, one day in 1928 I received a note from Dr Rogers inviting me to call at his house in Hutt Street after surgery hours as he had something to show me which he was sure would be of interest.

Naturally, I took the first opportunity to visit the Doctor, whereon he brought into the room a large jar with some white vegetable pickled in it. With a smile he said “Have you ever seen anything like this before?”

Well, there it was – this unique subterranean orchid from Corrigin, Western Australia, sent over by Mr C A Gardiner, the Government Botanist of Perth, who had realised the importance of this discovery.

The first plants were found in an area of virgin lane that had been rolled, burnt and then ploughed, which operation uncovered the white underground rhizomes. Mr John Trott, the discoverer, was puzzled by this strange plant growing around the stumps of Melaleuca uncinata R Br, common in the area, and sent it to Mr C A Gardiner. He, realizing the orchidaceous nature of the plant, visited the area, made personal observations and then sent a specimen to Dr Rogers for study, which led to the description of a now sub-tribe, genus and species of orchid – Rhizanthella gardneri Rogers.

Soon after this the Field Naturalists Society were to hold their Wild Flower Show in the Adelaide Town hall and attempted to have this unique specimen displayed there. However, the plant was too valuable to risk and an artist – Mr Lyall Lush – made a black and white drawings which was exhibited instead.

Within three years, on the east coast of Australia at Bulahdelah, another subterranean orchid Cryptanthemis slateri Rupp was unearthed. Unearthed is the word, for this one was unearthed by Mr Slater who was digging up rhizomes of Dipodium punctatum, the “Wild Hyacinth”, to attempt to grow them. All plants of the new orchid were found growing in association Dipodium. The importance of this find was such that Rev H I R Rupp was given a grant to travel to Bulahdelah to make further studies. This second find aroused worldwide interest and a German botanist suggested that the flowers of Cryptanthemis slateri were underground spikes of Dipodium. The morphology of the flowers soon disproved that theory.

Regarding this orchid, which Rupp named in 1932, Dr Rogers commented to me that he was sure that Rev Rupp’s parishioners must have had a very brief sermon the week Rupp received the first specimen of Cryptanthemis!

Dr Rogers then lamented that the orchid hunter has to add a plough and a pick to his orchid collecting equipment!!

 

Orchids come in ‘under par’ at Grange Golf course

With the development of cities here in Australia, many of our orchids were lost as habitat was cleared and the newly arrived settlers built houses and reconstructed the gardens they knew from the Old World; but the odd pocket of native bushland has survived.  Cemeteries and golf courses have often been the only refuge for remnant bushland.  One such refuge has been The Pinery, Grange Golf Club, the only known location of Oligochaetochilus arenicola (syn. Pterostylis arenicola) on the Adelaide Plains.  In the National Parks and Wildlife Act, this orchid is scheduled as vulnerable. The Golf Club left this site intact and has been supportive of the conservation efforts of the Threatened Plant Action Group who in turn have received assistance from the Native Orchid Society of SA and the Natural Resources Adelaide and Mt Lofty Ranges.

Typical of the rufus hood this Oligochaetochilus arenicola shows the sencesing leaves, pendent petals and hairs on the labellum. Photographer: H Lawrence
Typical of the rufushoods, this Oligochaetochilus arenicola shows the sencesing leaves, pendent petals and hairs on the labellum.
Photographer: H Lawrence

Below is a media release from the Natural Resources, Adelaide and Mt Lofty Ranges

Orchids come in ‘under par’ at Grange Golf course

News release
30 September 2015

A tiny remnant population of rare orchids which survives in a patch of bush on Grange Golf Course has increased 50% since last year, according to a new survey.

The survey conducted this month found 1200 individuals of the Sandhill Greenhood Orchid (Pterostyllis arenicola), a nationally threatened species which is considered critically endangered in the Adelaide and Mt Lofty Ranges region.

When surveys began 20 years ago, only about 100 plants survived at this site. But the latest survey has revealed the population is steadily increasing

The orchid comeback is thanks to decades of care by four groups involved with the annual survey: the Threatened Plant Action Group, the Native Orchid Society of SA, Natural Resources Adelaide and Mt Lofty Ranges, and with support from the Grange Golf Club.

The tiny fragment of native pine bushland in the middle of Grange Golf Course is one of the only known locations of this species within the entire Adelaide and Mt Lofty Ranges region, with other small populations known from near Wellington and Tailem Bend.

The orchid grows 10cm-25 cm high and produces hood-shaped flowers that are green and brown or red-brown with white markings. Most species of orchid flower for only a short period and for the Sandhill Greenhood, it will flower only for the next few weeks.

Grange Golf Course just happens to provide ideal conditions for the plant: red sandy soils and an over-story of native cypress pine trees.

Dedicated project partners have tackled the main threat to orchids – suffocation by Perennial Veldt Grass and Soursob weeds – through years of patient hand weeding.

The orchid comeback is a great success story of collaboration across the community to save one of our state’s tiny floral gems.

As a demonstration of nature’s interdependence, conserving the Sandhill Greenhood also means conserving a particular mycorrhizal fungus that must be in the soil for Sandhill Greenhood seeds to germinate. In addition, the flowers must be pollinated by a particular type of insect, the fungus gnat. The gnat is attracted by the orchid’s pheromones and tries to mate with the flower, only to find itself loaded up with a packet of pollen which it then transfers to the next flower as it continues its romantic adventures.

While the survey results are good news, the Sandhill Greenhood population is still precariously small, and it is hoped that as the population grows, so do the options to secure the species into the future.

South Australia has over 260 species of orchids, including 50 species of greenhood.

For a free colourful field guide to local orchids, go to http://www.naturalresources.sa.gov.au/adelaidemtloftyranges/home and search for ‘orchid’.

An Examination of Two Rufoushoods

This week’s post is taking a brief look at a paper by Noushka Reiter, Mark Clements and Kate Vlcek which appeared in Muelleria, Volume 31: 69 – 76, 2013.

Titled “An examination of Pterostylis xerophila (Orchidaceae) and the confirmation of P. lingua as a new species in Victoria” this paper seeks to ascertain whether the records collected are correctly identified, that there are differences between them both in morphology and associated vegetation.

Both P. xerophila and P. lingua are found in South Australia where they are known, respectively, by the synonyms Oligochaetochilus xerophilus and O. linguus. In fact the type specimen for O. xerophilus is from South Australia.

In the introduction, the authors give a detailed description of Oligochaetochilus otherwise known as the ‘rufa group’ which differs from Pterostylis, in the strict sense, in several features. Some of the main features of this group are:

  • Basal rosette of overlapping stemless leaves
  • Leaves senesced, withered and died, by flowering
  • Erect multi-flowered
  • Flowers
    • Lateral sepals
      • hang down
      • basal half joined
      • tips become long and threadlike
    • Labellum
      • is very mobile
      • has obvious long white hairs and often short hairs as well
Typical of the rufus hood this Oligochaetochilus arenicola shows the sencesing leaves, pendent petals and hairs on the labellum. Photographer: H Lawrence
Typical of the rufus hood, this Oligochaetochilus arenicola shows the sencesing leaves, pendent petals and hairs on the labellum.
Photographer: H Lawrence

Later in the articles, the differences between the two species are discussed. There is much of interest concerning the two species but one outcome of the research was to establish that P. lingua (O. linguus) had been incorrectly identified in the records and by correcting the names of the specimens the authors were able to confirm that it did occur in Victoria.

To find the answer to the authors other questions, read the paper

And for those that need a glossary of the terminology used, click here

For images of P. xerophila (O. xerophilus) click here

For images of P. lingua (O. linguus) click here

Greenhood Pollination Strategy

Since orchids, and Australian orchids in particular, first came to the attention of the western world in the 1800s researchers have been fascinated by the so many different aspects of the orchid’s morphology and life cycle. One area of interest has been that of how orchids are pollinated. The mechanism of pollination has not always been clear as the orchids seem to use different and complex methods.  From time to time various papers have been published of observations by researchers.

One such paper was published in the Annals of Botany 113: 629 – 641, 2014 titled ‘Caught in the act: pollination of sexually deceptive trap-flowers by fungus gnats in Pterostylis (Orchidaceae)’ by R D Phillips, D Scaccabarozzi, B A Retter, C Hayes, G Brown, K W Dixon and R Peakall.

The ‘question and answer’ style of the paper helps with ease of reading and is worthwhile perusing, even for the lay person. The accompanying VIDEO is also of interest.

The essence of the paper was to establish whether sexual deception was used to facilitate pollination.  The species researched was Pterostylis sanguinea (syn. Urochilus sanguineus) and the researchers confirmed that this did happen.  Their research showed that the attraction for the insect came only from the labellum which exuded an alluring chemical.  P. sanguinea has a mobile hinged labellum which is a feature of other sexually deceptive orchids such Paracaleana, Caleana, Arachnorchis.

Urochilus sanguineus RWL
Pterostylis sanguinea syn. Urochilus sanguineus with the untriggered labellum
Urochilus sanguineus RWL(1)
Pterostylis sanginea syn. Urochilus sangineus with a side view of the labellum