Australian orchids – Page 11

July 2016 Winning Picture

1607 sm RWL Corysanthes diemenicus.jpg

This month there were four very different species. Two were from Western Australia, Pauline Meyers’ Caladenia longicauda and Lorraine Badger’s Thelymitra pulcherrima, and the other two from South Australia, Rob Soergel’s Bunochilus viriosa and Robert Lawrence’s Corysanthes diemenicus which was the winning picture.

Corysanthes diemenicus is a very common winter orchid but this one is unique as instead of one flower as is normal there are two! So is it a new species? No, it is a freak; the technical terminology is teratologic.

Of the various plant families, the mint and orchid families (Theissen 2006) are well known for producing teratological plants, that is, plants that are grossly abnormal or deformed. Bates (2011) divides such abnormalities into five categories – peloric, teratological freaks, monstrosities, colour variants and throwbacks. All of them are congenital abnormalities which may be a result of unknown genetic malfunction or viral infection in the early developmental stages of the plant. Based upon this division, Robert’s picture is a monstrosity. This type of double flower is more likely to be found in self-pollinated plants for example Pterostylis foliata often produces more than one flower.

Most freaks are random, they come and go but peloric freaks are interesting. An early meaning of peloria was an irregular feature that becomes regular (Walker 1879) but in the orchids the meaning has been narrowed to refer to an “abnormality of the labellum that is of a similar shape and colour of the petals” (Australian Orchid Genera 2006) or more precisely an abnormality of the inner tepal whorl (the petals) wherein the petals can take on the appearance (in part or full) of the labellum, or the labellum takes on the appearance of the petals. One naturally occurring semi-peloric species is Calochilus imberbis. In recent years, orchid growers have cloned peloric freaks using a technique called mericlone to produce new cultivars eg Rhyncolaelia digbyana var. fimbripetala.

Freaks may be interesting but they are temporary so if you spot something unusual in the field look around at the surrounding orchids. If there is only the one or two individual or one colony, then it’s likely to be an abnormality rather than a new species.

Thank you to Greg Steenbeeke for checking this article.

Reference:

Bates, R. J., ed. (2011). South Australian Native Orchids. Electronic version, 2011. NOSSA

Jones, D L et al, (2006) Australian Orchid Genera, an information and orchid identification system, interactive CD-ROM

Masters, M T (1879) Vegetable Teratology http://www.gutenberg.org/files/23354/23354-h/23354-h.htm accessed 3rd August 2016

St George, I (2007) Monsters, Freaks, Retrogrades and Primitives http://www.nativeorchids.co.nz/Journals/103/page5.htm accessed 3rd August 2016

Steenbeeke, G, personal communications

Theissen, G (2005) The proper place of hopeful monsters in evolution biology http://carah.sweb.cz/xx12295.pdf accessed 3rd August 2016

Gleanings From the Journal #3 – Native Orchids The Epiphytes: August

The following article is from Vol. 32 No 7 August 2008 Journal of the Native Orchid Society of South Australia Inc.

Native Orchids. The Epiphytes: August.
Steve Howard

Movement of our natives towards flowering is often rapid. How often do we look at our plants thinking that they will never be out in time then take a look the week after and they have doubled in size. Dendrobium speciosum is a classic example of this. One minute the plant is covered in acorn like flower buds then a week later there are bunches of flowering buds everywhere. There is the temptation to force them on but I would leave that until the last two weeks prior to show before making that call. Then we have the Sarcochilus. These can stay in bud for months and not do a thing then suddenly they are away.

On the epiphyte side we should have a heap of buds everywhere on the flowering plants. They key is to keep these under cover and away from rain and also slugs and snails that have a nasty habit of chomping into them. Rain exaggerates fungal problems that will rot out a flower spike overnight. Also avoid temperature extremes, especially once the buds start showing on a lengthening spike. Bud drop occurs quickly and the loss of even one bud will sway the judge’s decision. Even and strong light now becomes important especially for those epiphytes with Den. speciosum and Den. kingianum in the background. The reason is we need to create strong upright racemes to support the flowers. No point having the spikes hanging over the side of the plant and then have the flowers doing the same. Some species do have this trait and as such do not make very good parents if this trait is passed on in hybridisation. I like my flowers to look at me and cannot see the point in lying on the ground and looking up at the plants on the bench. Strong light will assist this spike development as does the potassium and potash in the fertiliser. This is also a reason we tend to avoid high nitrogen feeds in our feeding programme. Even light is also important in order that the flowers will be evenly distributed around the pot as opposed to all facing the one way. Hanging flowering plants is one way we can get this even light.

Now is also a good time to clean up our plants before flowering. Remove husks over the canes, remove dead leafless canes and trim and clean the leaves. It is easier to do this now whilst the spikes are on the small side. Also give the pots a scrub too. All of these tips will help make things a little easier when it comes time to prepare the plants before show. Also make sure you have some fresh topping for the pots. It’s these little things that helps improve the presentation of our plants.

Only remove leafless canes if you think they have completed their flowering potential as many will flower for years after losing leaves or if the cane affects the appearance of the plant. If the forward growths are struggling under no circumstance remove the leafless cane unless it is absolutely dead as the struggling plant would be relying on stored nutrients in this cane to survive. I would then concentrate on why is the plant in the state in the first place.

Even though we are two months away from re potting and dividing our plants it is now time to take stock of what plants will be potted on, divided or sold off on the trading table. That way we can arrange pots, mix etc in preparation. The other thing I am looking at now is where am I going to move my plants this year. Last years heat exposed many plants that are susceptible to heat and with the probability that this will happen more frequently in the future there is the need to move these prone plants from where they are at present. Leave them where they are and the same thing will happen again. There will also be the need that these tender plants be removed from the collection and the emphasis placed on more hardy species and hybrids.

Watering will be dependent on the hybrids you grow and where the parents originate from. Most of the hot/cold type have the tropical hard cane types in the breeding eg Den. bigibbum and these require dry winters so we need to take this into account here. I do not dry them out completely but then again don’t water them frequently either. I aim for slightly moist at all times to keep the roots in good condition. The others with Den. speciosum, kingianum, falcorostrum all come from cooler climates that receive winter rains and as such can handle being damp over winter. Avoid over wetness as this will be to the detriment of the plants. These plants require a short dry period after flowering to mimic the same dry spring period experienced in the areas where most of them come from. I find that with our reduced rainfall of late, nature provides my plants with enough water apart from the mounted plants that get the odd mist or squirt. Any watering should be confined to the warmer part of the day after lunch. Early morning squirts with water from a hose that has been sitting on a frozen ground all night will not do your plants any favours. Feeding during these cooler months is infrequent and if you miss them for a month or more will not cause too many issues. Plants under cover get watered every couple of weeks and these are usually the hot colds.

You will have a few late season new growths reaching full size. Keep an eye on these as they are very prone to rot when water sits in the axils of the new growths. If you notice a growth go reddish or yellow it is a good bet that it has rotted. You can cut the growth off below the infection and treat with a fungicide. I then dry the plant out as a precaution and take a mental note. This plant will always be prone to attack.

My plant of the month is Den. aemulum, the feather orchid. This compact growing epiphyte comes from central NSW (New South Wales) to Qld (Queensland) and comes in 2 forms. The iron bark form strangely enough grows on the iron bark tree, a heavily permanent barked member of the eucalyptus family. It has small cylindrical psuedobulbs that grow in a radial pattern topped with two small and rather thick leaves. Small white clusters of flowers that go pink as they age are borne apically over several seasons from the one cane. The other form commonly seen is the brush box form. This is the long caned variety and the two are found in similar areas. These are not often seen in collections and have the habit of slowly fading away in cultivation unless their requirements of light, a suitable host and conditions are met. I have several plants on different hosts and the results are mixed. The best plant grows east on a slab of hardwood in a rather protected spot and is the brush box form. The iron bark forms appear to struggle on mounts of Callistemon and paperbark. Maybe it is the acidic gummy excretions from the bark of the ironbark that are missing. These plants have not been used in hybridisation very much as they do not have the traits that hybridists are looking for. Nevertheless I find them a very attractive flower when grown into a specimen plant and they will always have a place in my collection. They are not easy to obtain and generally restricted to those that have permits to collect them from the wild.

Next month is September and with it the warming weather and a profusion of flowers. We will look at a few tips to help with the presentation of show flowers but also look back at those that did not flower well or flower at all and see where we can improve and what went wrong.

Epiphytes in flower (1) — Annual NOSSA Spring Show

Orchids the Flagship Plant Group: How Do We Protect Them?

This week’s post is taken from the IUCN SSC Orchid Specialist Group Facebook post concerning Resolution decided upon at the final session of the International Orchid Conservation Congress Conference, held in May 2016 at the Kadoorie Farm & Botanic Garden, Hong Kong

It was posted by Michael Fay of Royal Botanic Gardens, Kew. He is also the Chair of the IUCN SSC Orchid Specialist Group. According to their website, “The Orchid Specialist Group is a global network of experts who volunteer their time and expertise to build a scientific and practical foundation for the conservation of orchids (Orchidaceae).”

(A list of the meanings of acronyms appears at the end of this post.)

Michael’s post follows

Here are the Resolutions from the final session of IOCC VI in Hong Kong:

03 KK sm Sarcochilus falcatus Mt Banda Banda

Orchids are a flagship plant group with a high profile in human culture. They are known from all vegetated continents on earth but their occurrence reflects patterns in the global distribution of biodiversity and their intricate ecological associations, particularly with pollinators and mycorrhizal fungi, reflect sensitive ecosystem processes. Accordingly, orchids are indicators of ecosystem and climate health. Many orchids and their associated biota have been exposed to a variety of threats as a direct consequence of human-driven global change, with almost half of the ca. 27,000 known species now potentially at risk of extinction. Delegates of the IOCC support all efforts to research and mitigate these threats and secure environments on which orchids depend, and are committed to achieving meaningful conservation by recommending that:

The creation of orchid enhanced habitats is a priority for ecological restoration.
Enhanced in situ orchid protection requires the creation of orchid reserves. These will benefit a wide array of other species and biological communities and can be financed through various public and private sources.
The international and domestic wild plant trade is widely recognised by governments and civil society as a major threat to the persistence of many orchid species, and that its curtailment requires concerted government action and enforcement.
The propagation and cultivation of threatened orchids by small and local orchid enterprises should be supported for the sustainable production of orchids used in horticulture, medicine and food.
Orchid cultivation should be licensed and audited by government or other government-approved body through a national (or international) accreditation scheme that specifies adequate safeguards to ensure best practice. Propagated orchids should be traceable and distinguishable from wild orchids so as to minimise the risk of laundering wild plants.
National, regional and international networks should be established and strengthened for promoting in situ and ex situ orchid conservation.
The next generation of orchid taxonomists, ecologists and conservationists is nurtured through improved training, education, publicity and awareness-raising programmes.
Paracaleana minor (Little Duck Orchid) Photo: David Manglesdorf
Members shall strengthen the work of OSG by:

Facilitating and conducting national and global Red Listing of orchids, and contributing to the Sampled Red List Index (SRLI);
Monitoring and reporting on the illegal trade in orchids to national enforcement agencies and to TRAFFIC;
Reviving Orchid Conservation International as a vehicle for web-based education and channelling funding to orchid conservation programmes, along the lines of Birdlife International;
Embracing social media and other web-based interactive tools as dynamic and effective means of stimulating communication, raising awareness and building networks;
Using citizen science as an effective means of motivating individuals and amateur groups to record orchid occurrence (e.g. OrchidMap, iNaturalist) and help scale-up the collection of verifiable data;
Establishing and maintaining a global database of orchid reintroductions (including both successes and failures) and ex situ orchid collections that can be accessed and updated by members and which is linked to the IUCN Reintroduction Specialist Group;
Creating new sub-groups focusing on trade and molecular identification, to reflect important cross-cutting themes and challenges.

Thanks to Stephan Gale and Phil Cribb for producing the final version of these.

Calochilus cupreus (Bearded Orchid) Photo: Helen Lawrence

IOCC VI refers to the International Orchid Conservation Congress Conference was held in May 2016 at the Kadoorie Farm & Botanic Garden, Hong Kong

IUCN: International Union for Conservation of Nature

OSG: Orchid Specialist Groups

SSC: Species Survival Commission

TRAFFIC: Trade Records Analysis of Flora and Fauna in Commerce

Orchid Specialist Group Website: http://www.iucn.org/species/ssc-specialist-groups/about/ssc-specialist-groups-and-red-list-authorities-directory-7

Caladenia procera

Orchid Hunter Visits Kuipto

The following video is by Orchid Hunter, Julian Pitcher. Julian is concerned about the conservation of orchids and is also keen to teach others about Australia’s unique orchids. At the time of the visit, Julian was resident in Victoria; now he resides in Queensland. Enjoy an interstate visitor’s view of our beautiful orchids.

June 2016 Winning Picture

1606 sm RM Caladenia cairnsiana

It is always good to see other members submitting images for the competition. This month Rob Soergel entered Urochilus sanguineus growing with Bunochilus viriosus and Ros Miller a Caladenia cairnsiana. Others were Rob and Jenny Pauley’s mass flowering of short Urochilus sanguineus, Pauline Meyers’ Arachnorchis cardiochila hybrid (possibly with A. strigosa) and Lorraine Badger’s Diuris corymbosa.

The winning picture taken by Ros Miller C. cairnsiana (Zebra Orchid) is one of Western Australia’s unique and interesting orchids. It was first collected by Baron Von Mueller (Victorian Government Botanist 1857–1873) from the Stirling Ranges and subsequently named in 1869 after the Rev Adam Cairns a Melbourne Presbyterian minister who promoted “various philanthropic studies”. In the 2000’s various synonyms were applied to the name, most notably Jonesiopsis cairnsiana (2003).

Many of the distinctive features of this species are readily seen in Ros’ picture – the non-clubbed, equidimensional short lateral sepals and petals which are hard pressed up against the ovary; the smooth, upswept labellum. What is not seen is the leaf which is erect large pale green with the bottom third usually irregularly blotched with red-purple.

Flowering from August to November, occasionally in clumps, these orchids are distributed over an extensive geographic area from Lancelin approximately 130 km north east of Perth, to Israelite Bay near Esperance some 775 km south east. They grow in a range of habitats from forests, woodlands, to mallee heathlands.

Interestingly for such a widespread and colourful flower, they are often missed being seen as they are ‘small and hard to see’.

References

Brown, A., et al,(2013) Field Guide to the Orchids of Western Australia. Perth, WA: Simon Neville Publications

Hanson, Kim (2016) WANOSCG Facebook conversation July 2016 https://www.facebook.com/groups/377740182396565/

http://www.orchidspecies.com/caladcairnsiana.htm accessed July 6 2016

http://members.iinet.net.au/~emntee/HISTORY_OF_ORCHID_COLLECTING.htm accessed July 6 2016

Archer, W http://esperancewildflowers.blogspot.com.au/2009/09/zebra-orchid-caladenia-cairnsiana.htm acc 12 July 2016

Culture of Fungi Dependent (FD) Terrestrials

This is the last of the three terrestrial fact sheets in Culture Notes that NOSSA has produced on growing terrestrial orchids. All three facts sheets can be downloaded – Click on the following for Fungi Dependent, Slow Multipliers and Fast Multipliers.

Orchid 1 Arachnorchis tentaculata — Arachnorchis tentaculata, common name King Spider Orchid or Large Green Comb Spider Orchid

FLAGBEARER SPECIES: Caladenia tentaculata (synonym Arachnorchis tentaculata)

Some 3/4 of Southern Australian terrestrial orchids are fungus dependent throughout their life cycle. Orchids that are fungus dependent have very specific cultural requirements. The fungus must be grown in the pot with the orchid. Sometimes a third entity such as a shrub or tree is involved in the fungal relationship.

A minimum disturbance culture is used.

Limited numbers are available each year. Other fungus dependent species are rarely available. Those in cultivation have mostly come from rescue digs in the past. NOSSA has started a seed kit project to help overcome this vacuum.

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. 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: 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.

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. FDs are mostly spring flowering and like higher light intensities at flowering time. flowers may have pale colours if placed in heavy shade, even temporarily, when buds 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.

POLLINATION/SEED COLLECTION: FDs seldom multiply so must be propagated from seed.

Flowers on the strongest plants of the same species growing in pots are cross pollenated by hand to set seed pods. The flowers collapse in a day of so and pods ripen in 4-8 weeks. Pods are collected as they change colour from green to brown, which happens quickly on a hot day in October/November. Tea bags can be tied over the pods to catch the dust like seed if frequent visits to site are not possible.

Pods are stored dry in paper envelopes indoors over summer. Seed can be sprinkled on mother pots or scattered on bush sites.

SEEDLING CARE: Seedlings can be raised by sowing seed around potted mother plants.

At Easter time, just before the rainy season begins, the dust-like seed is mixed with fine sand in a pepper shaker (minimizes seed loss) and sprinkled on top of the pots and watered in. Germination occurs in Autumn/Winter as that is when the fungi are most active. Tiny leaves appear from July to October. The seedlings form miniscule tubers on droppers about 1 – 2cm below the surface. Seedlings take up to five years to reach flowering and are best left undisturbed until larger.

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.

REPOTTING: The plants are not repotted but left in the same pot year after year.

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.

A thin layer of new leaf litter is placed on top of the existing leaf litter each summer to feed the fungus. Chopped gum leaves or sheoak needles are suitable.

FERTILIZING: NO FERTILISER

OTHER CULTURE NOTES:

Bratz no longer …..

There comes a time when one needs to just sit back, relax and smell the roses … well in this case the orchids. This is just what the dolls from Tree Change Dolls did.

Group

Sonia Singh, a Tasmanian artist, has been recycling old Bratz dolls giving them a down-to-earth style so different from their previous creation. She obviously loves nature and this is reflected in the transformation of the dolls. The dolls are as appealing as the orchids she photographed them with.

Drawing lessons — Friends enjoying the orchids together

Between the Orchids — Just between you and me …

Ready to draw — Who needs an ipad when I have pencil and pad.

With Spotted Sun Orchid — Spotted Sun Orchid and me

Sonia uses some of the money from the sales of the dolls to support various charities. In April 2016, she donated 10% of her sales to the Tasmanian Land Conservancy.

Keep up the good work Sonia. 🙂

BTW for those who are interested in the transformation, below are some before and after shots of the dolls featured in this post.

Before and After

To see other dolls, visit her site treechangdolls.com.au

Note: all images are from Sonia’s website.

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.

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.

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

OTHER CULTURE NOTES:

FAST MULTIPLYING TERRESTRIALS
FUNGI DEPENDENT TERRESTRIALS

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

May 2016 Winning Picture

1605 sm PM Caladenia flava

There were four entries this month with two from Western Australia Pauline Meyers’s Caladenia flava and Ros Miller’s Caladenia longicauda sbsp. eminens; one local Greg Sara’s Pheladenia deformis; and one from the Australian Capital Territory, Lorraine Badger’s Cyanicula caerulea. The winner was the Caladenia flava.

If I was to think of an orchid that represents Western Australia it would be hard to choose between the Queen of Sheba and this one.

With its long flowering season (July to December) it is Western Australia’s most common and widespread species; being found in the south west triangle of the state from Kalbarii to Israelite Bay; in habitat as variable as the coastal heathlands through to inland rocky outcrops; from forests to swamp margins. Being so prevalent, it is not surprising that it was amongst one of the first Western Australian orchids collected in September to October, 1791 by the ship-surgeon and naturalist, Archibald Menzies. It was subsequently named in 1810 by Scottish botanist Robert Brown.

C. flava is one of the five species belonging to the subgenus Elevatae. The other four being C. marginata, C. nana, C. reptans (all WA endemics) and C. latifolia which is widespread across southern Australia. All five species have the same characteristic feature of the calli joined together on a raised plate near the base of the labellum. C. flava is distinctively and predominately yellow whereas the others are pink or white.

C. flava has two pollinators, native bees which are lured deceitfully to the non-existent nectar and scarab beetles (Neophyllotocus sp.). As they share the same pollinators, C. flava often hybridizes with C. reptans and C. latifolia, producing very colourful offspring.

Observations have led orchidologists to divide C. flava into 3 subspecies. These differences are based upon floral morphology. but curiously they each have their own separate distribution.

References:

Brown A, et al, 2013 Field Guide to the Orchids of Western Australia

Hopper, SD & Brown, AP 2001b Contributions to Western Australian Orchidology: 2, New taxa and circumscriptions in Caladenia (Spider, Fairy and Dragon Orchids of Western Australia), Nuytsia 14:27–314.

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.

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

OTHER CULTURE NOTES:

SLOW MULTIPLYING TERRESTRIALS
FUNGI DEPENDENT TERRESTRIALS

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

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