2014 September Winning Photograph

The winning picture was a single flower of Thelymitra epipactoides (Metallic Sun Orchid) taken by Rosalie Lawrence. This picture was cropped from a photograph taken on a mobile phone. Phones have come a long way since the days of Alexander Graham Bell!

Thelymitral epipactoides or Metallic Sun Orchid

T. epipactoides is a special orchid both in its beautiful colourings and that it is one of our rarest orchids. This endangered species has been well studied in an effort to prevent its demise with the result that there is an abundance of information about it. Recently, with the knowledge gained, Dr Nouska Reiter of the Australian Network for Plant Conservation (ANPC) and her team have managed to cultivate 3,000 plants with the plan to re-introduce them back into the bush in the Wimmera area.

Following are some interesting points from two good sources, which are the

  1. Biodiversity Information Resources Data page  (quotes in blue)
  2. Species Profile and Threats Database page  (quotes in brown)

 

Life Cycle

  • (2)……can remain dormant as a tuber in the soil for up to nine years ……….

(But once a plant has flowered)

  • (2)…….Plants can produce flowers from their second year of growth onwards for up to four consecutive years, but no more. Individual plants can remain dormant for up to two years then grow to produce flowers, but if dormant for four years or more, plants generally do not reappear. …..
  • (2)…… Detailed monitoring suggests that mature plants only live for about 10 years before dying (Cropper 1993). ……..
  • (2)……..flowers open when the relative humidity is lower than 52%, air temperature is above 15 °C, and there are clear skies ………….
  • (2)……..Flowers remain for up to four weeks but wither a week after pollination ……
  • (2)……. fungus is required to initiate successful seed germination (Calder et al. 1989) and seeds cannot survive more than two weeks without associating with the fungus ………

Plant Information

  • (1)…….Flower colour is highly variable, brown, copper, blue and green being the main colour groups which are determined by the proportion of red, blue and green epidermal cells, some of which are reflective giving a metallic appearance. …….
  • (2)….The leaf is loosely sheathing ………
  • (2)…Mature non-flowering plants have slightly narrower leaves to 51 cm long and not sheathing …
  • (1)………Flower colour is highly variable, brown, copper, blue and green being the main colour groups which are determined by the proportion of red, blue and green epidermal cells, some of which are reflective giving a metallic appearance. ………

Topography:

  • (2)…. is undulating plains, crests of hills, gentle slopes of low broad ridges and at the bottom of broad, shallow swales (Obst 2005). It grows in sandy soils over a clay subsoil, with these soils having a tendency to become waterlogged in winter and spring, and drying out in summer and autumn ……
  • (2)…..This species is a post-disturbance coloniser, utilising early successional stages after disturbance events such as human activities, fire, animal activities such as scratching of the soil, or associated vegetation disturbance. ……
  • (2)……..requires open sites for flowering and seedling recruitment (Calder et al. 1989). ………

Population Size

  • (1)……Population estimates vary from about 1050 plants in Australia (DEH 2006), to less than 3,000 plants (Coats et al 2002). More recent assessments suggest the population could be less than 1500 plants in the wild …….
  • (2)……In the Murray Darling Basin and South East Regions of South Australia there were ten populations of the Metallic Sun-orchid recorded in 2004 by Obst ……..

 

Reminder – November theme is Orchids and Insects (Spiders and other such critters are honorary insects)

Orchid Etiquette – Tread Carefully

An important first lesson to learn when out orchid hunting is to watch where you put your feet.  In this video the Orchid Hunter explains the how and why for watching where you step.

Related Article

Protect Our Orchids – Stay On the Path

Australian Orchids and the Doctors they Commemorate Part 6 of 20

Archibald Menzies (1754 – 1842)

A British navy surgeon who circumnavigated the globe from west to east with Captain George Vancouver, in the tumultuous voyage of 1791 to 1974, explored extensively in south-west Western Australia, and was later president of the Linnean Society of London; his name is recorded in the names of banksias (including the firewood Banksia [Banksia menziesii]), orchids and mosses of the King George Sound hinterland which record his service to Australian botany.

Orchid species: Leptoceras menziesii (=Caladenia menziesii)

 

This orchid is the emblem of Native Orchid Society of South Australia

Australian Orchids and the Doctors they Commemorate Part 5 of 20

Having looked at the background, Professor Pearn documents the individual doctors and orchids.  In the original paper the doctors were listed alphabetically but these posts will be in chronological order based upon the doctor’s year of birth.

Daniel Solander (1733 – 1782)

A medical student in Sweden and London, and botanist-librarian on the Endeavour voyage to Austalia (1769 – 1771); his name is commemorated in the names of Australian species of Aciacia, Banksia and Geraniums.

Orchid species: Orthoceras strictum (= Orthoceras solandri)

The type specimen is from New Zealand.

 

Where in the world would you find an orchid?

In almost a word – every continent except the Antarctica.

Orchids are amazing, we expect to find them in the tropics but they can be found anywhere from the cold climes of Alaska to the semi-arid edge of the Australian deserts.

An Interactive Key to Australian Orchid Genera has an excellent chapter on habitats of Australian orchids.

15 habitats are listed with a list of the type of orchid likely to be found there.  The vast majority of Australian terrestrial orchids are found in either lowland (less than 500 metres altitude), in coastal regions or in open forest/woodland.  There are none in the Red Centre.

April 2014 Winning Photo

Thelymitra crinita

With a common name of Queen Orchid, Thelymitra crinita is aptly named, for the flower has a quiet regal air of elegance and delicacy that would appeal to many people. Lorraine Badger who took this photograph was one of those people.

T crinita is a common Western Australian orchid that can be found from Perth around to Albany with a disjunct area near Esperance. Back in 1839, it was one of 60 orchids named by John Lindley in ‘Appendix to the first twenty-three volumes of Edwards’s Botanical Register together with A Sketch of the Vegetation of the Swan River Colony’ page xlix. Though the register is written in English the species description is in Latin, here reproduced for all those Latin buffs –

(214)  helymitra crinita; folio radicali oblongo apiculato glabro, raceme cylindraceo, floribus purpureis, cuculli laciniis lateralibus barbatis unguiculatis intermediâ fornicatâ emarginatâ dorso glanduloso-villosâ

On a recent visit to the South Australian State Herbarium, Michelle Waycott, Chief Botanist, explained that there is a strict botanical standard for describing a species. You may  be pleased to  know  that  at  the  18th  International  Botanical Congress in Melbourne, Australia in July 2011, it was determined  that  from  the  1st January  2012  it  was  no longer mandatory for descriptions to be in Latin only. English can now be used.

South Australian Terrestrial Orchid Culture Notes Part Four of Four Parts

Re-establishing Orchids

Replanting in bushland should be restricted to orchid species that grow or once grew in the local area. No hybrids please.

If planting out in the garden or bush, choose a location with good air movement and winter sun and a thin layer of surface mulch. Slashed native ground cover is good. Native terrestrial orchids cannot stand competition from weeds, grasses, slugs and snails and scratching blackbirds (all introduced pests). They will rot away in dense weeds or dense understory plants. If in a frost prone area they may need overhead protection from a shrub or trees. For plants in growth, dig out a hole a little bigger than the tube. Knock out the tube and insert the contents into the hole and backfill with as little disturbance as possible. Dormant tubers can be planted in a furrow, 50mm or more deep, and backfilled just like planting beans. Water in. The colony forming species will spread out and form patches of plants over a period of several years.

Orchid seed is like fine dust and can be mixed with fine dry sand to help spread it over a large area. Broadcast using a pepper-shaker over a suitable site. Results are dependent on the season and whether fungi are present. This method is slow to show results as flowers may not be seen for 5 to 10 years after seed is sown. More seedlings germinate if there are mother plants already growing.

Pot of Arachnorchis argocalla

A pot of Arachnorchis argocalla, 40 cm tall (Fungi Dependent)

To learn more about re-establishing orchids in the bush, visit the Vale Park Our Patch website to see the work being done by Heather Whiting and her team.

South Australian Terrestrial Orchid Culture Notes Part Two of Four Parts

 

Terrestrial Orchid Cultural Groups

Terrestrial orchids can be placed into one of three groups that have similar cultural requirements.

  • Fast multipliers with an annual increase rate greater than 1.5
  • Slow multipliers with an annual increase rate less than 1.5
  • Fungus dependent orchids survival rate less than 1

Fast multipliers (FM):

Fast multipliers are the easiest deciduous terrestrials to grow and potfuls are regularly seen at orchid meetings and shows. They multiply rapidly by forming 2 – 4 tubers per plant each year. They will take some fertiliser and grow better if repotted annually. It is usually not commercially viable to grow seed of these in flask. They will grow well in premium potting mix from your local hardware store with some sand added. This group contains many genera including Acianthus, Chiloglottis, Corybas, Cyrtostylis, Diplodium, Leptoceras, Microtis, Pterostylis and some species from Caladenia, Diuris and Thelymitra.

Slow multipliers (SM):

Slow multipliers are not so easy because there is less room for error. Some very showy Diuris, Pterostylis and Thelymitra fall within this group. 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. They are more expensive because they have to be raised from seed in flasks. Flowering plants are hand pollinated and the seed collected just before the pods split open and the dust-like seed blows away. The pull-off-the-tuber method can be used with some Diuris and Pterostylis species to double plant numbers annually. Do not fertilise these except when repotting. Those with large tubers such as Thelymitra nuda and Diuris behrii should be the first to be repotted in November – December.

 

Fungus dependent orchids (FD):

Some of Australia’s most fascinating orchids rely on a symbiotic fungal association to obtain nutrients from the soil as these orchids have virtually no roots. The majority of Australia’s terrestrial orchids are in this group and many are rare plants as they seldom multiply. We talk about survival rates for these orchids that are normally less than one. Propagation is from seed. They have a reputation for being difficult to grow in pots. However some species have been kept alive in pots for nearly 30 years. Never use fertiliser because it can kill the fungi. They should be repotted only when the tubers reach or come out of the bottom of the pot or seedlings get too crowded. A new thin layer of leaf litter is added to the surface each summer to feed the fungi which is active near the surface. Flowers are hand pollinated to get seed. Seed is sprinkled on the pots each autumn and with good culture, seedlings will appear in spring around mother plants.

Since the fungus cannot be seen with the naked eye, the health of the leaves is used to indicate that the fungal relationship with the orchid is working. If seed is sown in autumn, by springtime, when mature orchids flower, there may be a new crop of tiny seedling leaves around the base of the large mother plants. The appearance of new seedling leaves around mother plants each spring confirms that the fungal relationship is healthy. Seedlings take 3 – 5 years to reach flowering size.

 

Important Rules

  • Use a mix that is at least 50% sand. The bottom of the pot can be pure sand.
  • Never use fertilisers (fertilisers can kill fungi).
  • Feed the fungus by adding new leaf litter on top of the old litter layer each summer. Chopped up sheoak needles or gum leaf stalks/nuts are recommended.
  • Do not repot unless absolutely necessary (eg the tubers come out the bottom of the pot, overcrowding, disease).

 

Pots of Thelymitra nuda cultivated by Les Nesbitt

Thelymitra nuda cultivated by Les Nesbitt (Slow Multipler)