May 2014 Winning Photo

05 PM T pulchemirra sm

Pauline Meyer’s winning photograph is a whole plant picture of Western Australia’s flamboyant Queen of Sheba Orchid.  It was taken at Eneabba, north of Perth and identified by a local as Thelymitra variegata but in consulting the books it would appear that it is the Northern Queen of Sheba, T. pulcherrima.  There are three species known as Queen of Sheba orchids in Western Australia – T. varigata, T. pulcherrima and T. speciosa.

T. variegata was originally named in 1839 by John Lindley but under the genus Macdonaldia.  In 1865 Ferdinand Mueller moved it to Thelymitra, later people began to separate it out to three different species* but it wasn’t until 2009 that Jeff Jeanes describeds T. pulcherrima and T. speciosa as distinct species from T. variegata.

All three species have a single thin spiral leaf and showy multi-coloured flowers.

T. pulcherrima and T. speciosa differ from T. variegata in the following points.

  • T. speciosa, begins flowering earlier, is a slightly shorter plant with fewer flowers (one, more rarely two) and although the flowers are a similar size to T. variegata they are even more colourful and the petals and sepals are distinctly different colours.
  • T pucherrima is similar in height to T. variegata but has smaller flowers with yellow, red, purple mauve sepals and pink purple mauve petals.  It too begins flowering earlier than T. variegata.
They all have distinct separate locations as reflected in the common names – Southern Queen of Sheba (T. variegata), Eastern Queen of Sheba (T. speciosa) and Northern Queen of Sheba (T. pulcherrima).  For some good images go to Retired Aussies or the Chookman
 
Finally there is one other species that is similar to these three and it is called Cleopatra’s Needle, T. apiculata.
 
  Thelymitra pulcherrima Theylmitra speciosa Thelymitra variegata
  Northern Queen of Sheba Eastern Queen of Sheba Southern Queen of Sheba
Distribution North of Perth between Lancelin and Dongara Between the Stirling Range and Condingup Between Perth & Albany with disjunct populations near Hyden
Flowering late June – early September late June – September August to September
Flower numbers 1 to 5 1 to 2 1 to 5
Flower height 150 – 350 100 – 200 mm 100 – 350 mm
Flower size 25 – – 35mm 30 – 50 mm 30 – 50 mm
Sepals Yellow, red, purple and mauve Yellow, red, purple and mauve Deep pink purple blotched
Petals Pink or purple and mauve Pink or purple and mauve Deep pink or purple and darker purple blotched
 
References:
Field Guide to the Orchids of Western Australia 2013, pages 425 & 427
I would like to thank Andrew Brown, co-author, for his help with this article.
 
* The name T. puchemirra is mentioned in the Western Australian Native Orchid Study and Conservation Group 2008 field trip report

South Australian Terrestrial Orchid Culture Notes Part Three of Four Parts

Maintenance throughout the year

Summer

  • During summer, very lightly water surface of pots weekly to prevent tuber desiccation especially if dormant seedlings are in the pot.
  • Divide overcrowded pots in summer. Tip out and break into slices like cutting a cake. Stand a slice in a new pot & fill spaces with fresh mix. Take care to keep the surface layer at the surface of the new pot.
  • Add fresh leaf litter to surface layer in January to February to March.
  • If surface moss gets too thick, peel it off and discard in summer.

Autumn

  • Start heavier watering of pots weekly from mid March.
  • Mix seed with fine dry sand and sprinkle on mother pots in April.
  • Water as required in autumn, winter & spring so that pots never dry out during the growing season yet are not soggy wet.
  • Leaves appear from Anzac Day to June.

Winter

  • Look for flower buds down inside the largest leaves from mid July onwards.
  • Look for new seedling leaves from August to October.

Spring

  • Enjoy and photograph flowers September to November.
  • Hand-pollinate flowers in September – October. Flowers collapse within days of fertilisation.
  • Collect seed pods as they turn brown just before they split open in November – December.
  • Dry & store seed over summer in paper envelopes kept indoors.
  • Allow pots to slowly dry out in mid – late November to induce dormancy and ripen tubers. Plants die down completely in summer to underground tubers.

For further information on growing fungus – dependent orchids refer to:

  • Orchids Australia’ February 2006, P58, or ‘The Orchadian’ Vol 15, Number 3, March 2006, P100.

Pot of Caladenia latifolia cultivated by Les Nesbitt

Caladenia latifolia cultivated by LN (Fast Multipler)

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)

 

South Australian Terrestrial Orchid Culture Notes Part One of Four Parts

Les Nesbitt is a founding member of the Native Orchid Society of South Australia and is our most experienced terrestrial orchid grower.  The following four posts on growing are from his notes and pictures .

 

Introduction

Australian terrestrial orchids have been grown in pots in Adelaide for more than 50 years. Nowadays with a wider range of species and hybrids available there are an estimated 300 cultivars successfully growing here. When the cultivation of the fungus dependent terrestrials is fully understood this number will increase dramatically.

Australian ground orchids are cool climate plants that 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 – 40°C max, 12 – 30°C min) conditions. All species like good air movement and will not thrive in a stuffy humid atmosphere especially if temperatures are high.

Growing Area

In South Australia, terrestrials are grown in shadehouses with 50% cloth on the roof and sides. This lets the rain soak the pots and flush out salts from tapwater use. Some growers add a second layer of 50% shadecloth in summer to lower pot temperatures.

It is very important that winter sun and breezes reach your plants so place the shadehouse away from the winter shadows of buildings and evergreen trees. A shadecloth cover or evergreen tree to the southwest and overhead will give protection from frost, hail and storms. Light frosts of -2°C do not worry the majority of species. Galvanised mesh benching about 750mm high will deter slugs and snails and is a convenient height for observing the pots. Watering with rainwater is better than Adelaide tap water. Fungi and orchids do not like salt.

Light

Some species prefer heavy shade, others full sunlight, but most will adapt to a wide range of light intensity. If the leaves and stems are weak and limp or if the 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 under dull conditions.

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. If pots are allowed to dry out during the growing season, the plants may go dormant prematurely.

Pests and diseases

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. Thrips, aphids, red spider and caterpillars may cause damage. Blackbirds can scratch out small orchids. Various rots can destroy plants. Orchids showing virus like symptoms should be burnt or dumped.

Fertilising

Be very careful with fertilisers because some terrestrials are easily burnt or even killed by overuse. Diuris and Pterostylis are very hardy and will benefit from weak applications of foliar feed in the early growth stages.

Repotting

The new tubers are produced in winter – spring. The fast multiplying types form several tubers per plant each year. Sometime in October – November, the leaves go yellow and then brown and dry, as the days get longer, hotter and drier in late spring. 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.

The pots can be knocked out and the tubers examined in summer without harm, in fact we find at the Nursery that the best results are obtained if the tubers are repotted in half fresh soil mix each year. Our 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. Repotting is normally done in November, December, January and February in South Australia. Ideal pot sizes are 125 – 150 mm standard plastic pots.

Keep the pots shaded and allow the pots to dry out between light watering 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. 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 are usually the first to appear in March followed by Diuris and Thelymitra in April, Caladenia in May and Corybas in June – July.

Sun loving species like Diuris, Microtis and Thelymitra prefer a brighter location for good growth. Corybas like the shadiest corner in winter.

 

 

Pot of Thelymitra Kay Nesbitt Cultivar copy

Thelymitra ‘Kay Nesbitt’ cultivar (Fast Multiplier)

 

Orchid Walks at Mt Lofty Botanic Gardens

For the last couple of years, NOSSA has been conducting spring tours at the Mt Lofty Botanic Gardens, South Australia, showcasing our beautiful native orchids to visitors far and wide.  They have come from not only Adelaide but from interstate as well as overseas from such countries as America, Germany, England and many others.  If you are planning to be in Adelaide during spring, then consider joining one of our walks, but for those who cannot attend here is a video for you.  So watch and enjoy …….

 

Australian Orchids & the Doctors they Commemorate Part 14 of 20

Richard Sanders Rogers (1862 – 1942)

An Adelaide physician, doctor-soldier and forensic pathologist who described 82 new orchid species (66 from Australia).

Orchids

Diplodium rogersii (= Pterostylis rogersii) or Curled Tongue Shell Orchid

Prasophyllum rogersii or Marsh Leek Orchid