What makes an Orchid and Orchid?

Orchid flowers are extremely variable in appearance, ranging from mimicking spiders, flying ducks, helmets, ants, etc. This variety also can cause some confusion. People have mistaken a different type of flower for an orchid and vis a versa.

This raises the question of what makes an orchid an orchid? With so much variety, how can they possibly belong to the same family?

Using orchids found in the Adelaide Hills, the following video shows three key features that helps identify a flower as an orchid. These three features are found in all orchids worldwide.

So watch and enjoy …

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Waiting for the rain …

Last year we waited for the rain. The rain heralds the start of the orchid season. Last year the season was dry, very dry. It was below average and it was hot.

So how did the orchids fare in the Adelaide Hills? The start of the season was slow with our first field trip not being until May 26 because of the lack of rain.

At the time, the smallness of the plants was noticeable with one specimen of flowering Leporella fimbriata standing no more than 2 cms. Normally  the flower stem can be up to 25 cms tall. This trend of smaller plants continued throughout the year.

The following two photographs show the difference in size.

Small Leporella fimbriata

A miniscule Leporella fimbriata near an ant nest

Leporella fimbriata sm

And on January 28, we came across the smallest flowering Dipodium pardalinum that we’d ever seen. Normally, this genus can grow up to about 100 cms in height but this one barely reached above the height of Robert’s shoe, ie, about 10 cms. True this was an exception but overall there not many plants, and even they were spindly and small in comparisons with previous years.

Below are two photographs illustrating the size difference

Small Dipodium pardalinum

A very tiny Dipodium pardalinum

Dipodium roseum

An average sized Dipodium

So what is the outlook for orchids for 2019? That will depend upon the rains.

When does the orchid season get going? Again that depends upon the rain but expect to see the autumn orchids about six to eight weeks after a good rain episode.

So we wait for the rains ….

Sarcs – Growing without the Nonsense!

The following article is from Volume 42 Number 10 November 2018 Native Orchid of South Australia Journal. Marg Paech, editor, has written an excellent summary based upon Kevin Western’s detailed notes which he has kindly supplied and is available here.

1510 sarcochilus cropped

Kevin Western, this month’s guest speaker didn’t hold back. He exposed some of the myths pedaled by good growers who misinform naive newbies or other growers.
Until about 1960 or thereabouts, the only Sarcochilus orchids that existed were in the bush where they had evolved and grown for all time and the only orchids that existed in people’s collection were bush collected so therefore all were species. No doubt, at times in the bush, there were hybrids made accidentally by pollinators or by other natural chance events. 1968 was the first time we can say for sure that there were hybrid Sarcochilus in existence.

Sarcochilus are native to the east coast of Australian and to Tasmania. There are about 25 species recognized and the number has grown recently with the splitting off of S. minutoflos.

The easiest species to grow for hobbyists generally are Sarcochilus hartmannii and S. fitzgeraldii. From their physical appearance and flowering time, flower shape and nature, it can be seen that they are closely related. Their natural environment can be matched in a pot by using a range of different potting materials (either solely or a mixture of) – suitable size pine bark, Perlite, cut up tree fern fibre, rice hulls and or sphagnum moss. Remember, they will grow on rocks, rubble or on various types of natural and artificial mounts!

03 KK sm Sarcochilus falcatus Mt Banda Banda

Sarcochilus falcatus

Humidity

Sarcochilus grow naturally where they do because of the balance between the suitable amount of reliable moisture in the form of rainfall and or dew; and those unavoidable moisture losses due to sun, heat and wind. We can replicate that by just giving our Sarcochilus regular waterings, and ensuring that our potting medium is coarse enough. An extra layer of shade in really hot summers can help, and by reducing wind movement by the location and provision of shade houses, we can create suitable growing conditions for our orchids. Frequent watering is the trick – retirees by hand watering and workers by sprinklers, misters on timers or thermostats or similar. Air movement is a must but here in sunny Adelaide we get plenty of it and in fact, too much movement has a drying effect.

Potting Mixes

The best mix for Cymbidium (sic)* orchids is a coarse, non-retentive medium – far better because they can be watered frequently – even twice a day or far more, and plants do far better. Even standing the pots in water during summer works wonders! Trial and error is the best way to learn, as experienced by Kevin.

Sarcochilus can be potted into clay balls used by hydroponics growers. Good, clean coarse pine bark also is fine.

1510 sarcochilus x velvet

Watering and Fertiliser

It is generally considered impossible to grow plants on mounts in shade houses etc in suburban Adelaide. Yet another myth! They grow exceptionally well, a fact that Kevin found out thanks to Kris Kopiki. It is more difficult to overwater a plant on a mount.

There are lots of myths about fertilizing. Using far more dilute fertilizer applied to a dryish mix and roots, Kevin has found to be far more effective. His policy is to fertilise weakly and frequently. Despite the hundreds of fertiliser options and brands available – they all are only better or worse
sources of those few essential substances which an orchid requires. The seaweed extract products are probably good as they seem to promote root growth. Keep it simple is the best option.

Summary

Our Sarcochilus have roots designed to grow attached to rocks or branches or twigs and are designed to catch and hold quite small water opportunities and they may benefit from drying out from time to time and for periods of time.

Coarser and less water retentive media are advantageous by enabling the roots to experience some drying as would occur in nature.

We are then able to water and fertilise far more often and our plants will grow better. We need to better understand what our preferred fertiliser’s strengths and weaknesses are so that we can better supply their needs more simply, more effectively and at lower cost.

Regular watering, wind control and shade improvement to avoid drying stress is far more sensible than hoping to reproduce and sustain high humidity.

Thank you Kevin for such a candid, down-to-earth talk full of good advice for growers

*In Kevin’s note he discusses his experience with Cymbidiums but Sarcochilus can also be grown with a similar medium.

sarco nugget gold rush seedling (1)edited

NOSSA Inaugural Calendar 2019

2019 Calendar Flyer sm amended.jpg

Every month, NOSSA holds a photograph competition. The entries were varied and beautiful but they were only being seen by the members at the meetings, so it was decided to showcase these lovely orchid images in a calendar.

The overall winner from 2018 would be on the front cover and we would select twelve from the fifty-one 2018 entries. The challenge was to select the twelve. This was done by having an on-line vote for the twelve most popular pictures. And I would like to thank all who entered and all who voted.

Having collated the votes to find out what was the most popular orchids, the next task was to design an informative calendar giving information about the South Australian orchids featured as well as significant NOSSA event dates and a very rough guide indicating when the orchids are likely to be flowering.

If you are interested in ordering a calendar, contact NOSSA as per the details on the flyer above.

Selecting Photographs for 2019 NOSSA Calendar

Every year, NOSSA holds monthly photograph competitions. This year, NOSSA decided to give the entrants an opportunity for their photographs to appear on a calendar. There have been 51 entries this year, so we are asking people to vote for the twelve images that they would like to see in a calendar.

To vote

  • Select the numbers corresponding to the twelve images that you would most like to see in your calendar
  • Indicate if you are interested in purchasing a calendar
  • Email – nossa.enquiries@gmail.com  (Subject Heading – Calendar)
  • Voting closes on Thursday 1 November 2018

The results will be collated to determine the twelve most popular images will go into the calendar. We plan to have the calendars available for purchase at the next meeting, Tuesday 27 November.

If you would like more details or see the images in a higher resolution, use the above email address to contact NOSSA.

2018 Thumbnails Photogrpahs for voting

Genus Plumatichilos

This week’s blog is from the Journal of the Native Orchid Society of South Australia, Volume 42 No 8. Leo Davis has been doing a series of articles aimed at helping members learn how to identify the orchids.

This article is about Plumatichilos, one of the segregate genera of Pterostylis. It has an unique labellum which sets it apart from the other Greenhoods. Leo wrote this article soon after David Jones named them in the Australian Orchid Review.  Will these names be accepted or not is a matter of waiting and seeing but it should be noted that they have been in manuscript form for many years. At the time of writing, they are not in the South Australian eflora.

Both the species discussed in Leo’s articles are from the Plumatiochilos plumosum complex or group.

Plumatichilos sp. Mallee Bearded Greenhood =Plumatichilos multisignatus

Plumatichilos sp. Woodland Bearded Greenhood = P. foliaceus

Unless otherwise noted, all images are Leo Davis.

Genus Plumatichilos.

Back in 1990 Bates & Weber placed all greenhood orchids in genus Pterostylis(1. pp118-143) where some of you and all Australian State Herbaria and certainly Janes & Duretto (3. pp260-269) would have them still be.  In 2001 Szlachetko erected the genus Plumatichilos.  In his Guide(4. pp286-339), Jones divided the greenhoods into 16 separate genera, these in two groups, each of eight genera.  One group all have the lateral sepals directed downwards (including Bunochilus and Urochilus) and the other eight all have them directed upwards (deflexed, as in Diplodium and Pterostylis).  Even those of you who reject the splitting and creation of the extra genera will concede that those placed in Plumatichilos, which have downward directed and partly fused lateral sepals (forming a synsepalum), are strikingly different in appearance to any other Pterostylis species.  The most obvious distinguishing features are the unique labellum and the two openings to the galea.

I had known just two species of Plumatichilos, both of which were undescribed.  I could recognise and distinguish them essentially because they grew in very different habitats and locations.  I used Bates’ tag names, Mallee Bearded Greenhood (Plumatichilos sp. Mallee Bearded Greenhood) (3. pp913-4) and Woodland Plumed or Bearded Greenhood (Plumatichilos sp. Woodland Bearded Greenhood)(1. pp915-916).   In recent weeks both (along with two other South Australian species) have been formally described.  They are now, respectively, Plumatichilos multisignatus(5. pp33-35) (Fig. 1) and P. foliaceus(5. pp30-32) (Fig. 2).  But, to a large extent, I still identify them more by the locations in which I find them than, to my eye, clearly discernable physical features.

Fig 1 P multisignatus Fig 2 P foliaceus
Fig. 1. Plumatichilos multisignatus. Monarto. Sept 10, 2012. Fig 2. Plumatichilos foliaceus. Para Wirra. Sept 11, 2013.

I had no idea what ‘barrier trichomes’ were but I saw that Jones listed them as the last of 13 dot pointed characters of genus Plumatichilos(5. p26).  Trichome simply means a hair growing from a plant epidermis.  They can be unicellar or multicellular and branched or unbranched.  The ‘barrier’ refers to its capacity to block and direct a pollinating insect to an exit path that puts it in the right posture to transfer a pollinium to the stigma (sticky receptive female part of flower).

Fig 3 Bunochilus prasinus June Niejalke Janes & Duretto, who reject the splitting of genus Pterostylis, divide it into two subgenera using the absence (subgenus Pterostylis) or the presence (subgenus Oligochaetochilus) of barrier trichomes on the column wings(3. pp262).  They place what I call Plumatichilos in the section V, Catochilus, of subgenus 2 Oligochaetochilus(3. pp266), and, yes, I see your eyes glaze over.  To them the Adelaide Hills ‘plum’ would be Pterostylis, subg. 2 Oligochaetochilus, Sec. V. Catochilus, species foliaceus.  Learning what ‘barrier trichomes’ are had me go back searching my photo library and I found images of the barrier trichomes in Bunochilus flowers that I had not previously spotted.  I have used and annotated a detail sent to me by June Niejalke. (see Fig. 3).

Fig. 3. Bunochilus prasinus. Sherlock (Type location for the species). Photo by June Niejalke.

As with all ‘true’ Pterostylis, the dorsal sepal and the two lateral petals, of the upside down flowers, are formed into a galea or cap (Fig. 1).  They are fused so closely that it can be hard to discern the join between the sepal and the comparatively small petals, especially in some less clearly striped flowers. (Figs. 1 & 2).

The typical Pterostylis galea has a single opening but in Plumatichilos there are two, a lower one, from which the uniquely formed labellum protrudes (and through which the pollinating male gnats enter) and an upper one (through which the pollinators exit) (4. p335), guided by the barrier trichomes (Fig. 4).  Through this upper opening you can observe the top of the column, including parts of it, the pollinia, the barrier trichomes, column arms and sometimes the stigma.  Two crossed filaments, in front to the pollinia, are column arms.

Fig. 4. Plumatichilos foliaceus. Scott Creek C.P. Sept 2015.

Fig 4 P foliaceus

 

Fig 5 P foliaceus.jpg The labellum (the modified third petal) (Figs 1, 2 & 5) is unlike that of any other Pterostylis sp.  It has a slightly flattened filament having a reddish-brown apical knob and two or three types of hairs along its length.  Jones describes the labellum of P. foliaceus as having three types of hairs(5. p30).  You may be able to see the short white ones (1 mm) at the base of the labellum in Fig. 5.  The longer (5-7 mm) yellow ones along the most of the length of the labellum are easy to see.  I am not sure that I can distinguish the shorter proximal (near point of attachment) yellow ones (1.5 mm).  In P. multisignatus Jones describes just two types of labellum hairs(5. p33) with the white basal ones absent, and two sorts yellow hairs, proximal ones to 1.2 mm and longer ones 5-8 mm.  To my eye, this character, two or three types of labellum hairs, is the only objective, rather than subjective , distinguishing feature between the two species that I regularly observe.

Fig. 5. Plumatichilos foliaceus. Scott Creek C.P. Sept 26, 2015.

In Fig. 5, I think that you can see that the hairs arise, in two parallel rows, not paired, from the sides of the flattened shaft of the labellum filament.

Fig 6 P foliaceus Fig. 6. Plumatichilos foliaceus in early bud. Scott Creek C.P. August 29, 2018.

Another generic character is ‘leaves sessile (no stems), ascending to erect, often with whitish or yellowish interveinal areas.’ (5. p26)  You may need to look very closely, in Fig. 6, to see these ‘windows’, mainly at the bases of the stemless leaves. 

 

References:

  1. Bates, R.J (2011). South Australian Native Orchids, DVD Issued by the Subediting Committee (NOSSA) on behalf of the
    Native Orchid Society of South Australia Incorporated.
    2. Bates, R.J. & Weber. J.Z (1990). Orchids of South Australia, A. B. Caudell, Government Printer, South Australia.
  2. Janes, J.K. & Duretto, M.F. (2010), A new classification for subtribe Pterostylidinae (Orchidaceae), reaffirming
    Pterostylis in the broad sense. Australian Systematic Botany, 23, 260–269.
  3. Jones, D.L. (2006), A Complete Guide to the Native Orchids of Australia, Reed New Holland, Australia.
    5. Jones, D.L. (2018), Six new species of Plumatichilos (Orchidaceae: Pterostylidinae) fromSouth-eastern Australia and a
    new species from New Zealand, Australian Orchid Review 83(4): 26-44.

Other articles about Plumatochilos can be found here and here.

Thelymitra Column Features Part One

The following article is the beginning of a series of discussions on identifying features of various orchid species/genera.

Thelymitra juncifolia

Thelymitra juncifolia

A previous blog (see here) referred to the importance of the column in Thelymitra but did not give details of the parts of the column which is the subject of this blog.

The columns in a Thelymitra (Sun Orchid) may be one of the main identifying features of a sun orchid and so this article looks at those features that botanists will often refer to in their descriptions.

Though we cannot physically dissect an individual flower, we can make use of photographs to spot the various features.

The diagram below is that of T. ixioides (based on the taxonomy of 1984) column whilst the photographs are that of T. juncifolia column (as T. ixioides is now considered to be limited to the eastern states). The column of these two are similar. One photograph will not give all of the features hence in this article the three photographs show all of the features except the viscid disk where the pollinia is stored. The stigmatic plate is sticky and receives the pollen for fertilization.

T juncifolia diagram photos sm

Most of the variations between the Thelymitra columns occur within the upper portion of the column. The post anther lobe can be quite varied. For instance, with T. ixioides/T. juncifolia the post anther lobe is not hooded. Some with hoods may have deep splits, whilst others form a broad fringe. Yet again, others have variations within the column arms such as having no cilia. This will be dealt with in further articles.

2018 August Winning Photograph

1808 sm JP Corysanthes incurva Penola CP

This month’s winner was Jenny Pauley’s photograph of a Corybas incurvus (syn Corysanthes incurva).

Before looking specifically at the species, it might well be worthwhile looking at the features that distinguish the Corysanthes (Toothed Helmet Orchid) group from Corybas (Spurred Helmet Orchid). The major difference appears to be in the flowers. The Corybas flower is dominated by the dorsal sepal which hides the labellum whereas with the Corysanthes the dorsal sepal and labellum are equally prominent although sometimes the dorsal sepal may be the less dominant. A less obvious difference occurs in the leaves. Corysanthes leaves have a fine point but this is absent in Corybas. Based on this only Corysanthes (Toothed Helmet Orchid) occurs in South Australia.

C. incurva, as part of the Corysanthes group, is interesting because the flower does not appear flared or toothed. But though the labellum curves in, it does initially start to flare, and it does have fine short teeth. In fact, in the early stages of the flower opening it can be possible to confuse it with the opening bud of C. diemenica. One of the differences between these two species is that the flower of C. incurva sits on the leaf with no clearly visible stem whilst C. diemenica is raised above the leaf with a visible stem.

This image of a typical Corybas from Colin Rowan, retiredaussie.com , helps to see the difference between Corysanthes and Corybas.

https://i1.wp.com/www.retiredaussies.com/ColinsHome%20Page/OrchidsNSW/Corybas/Corybas%20dowlingii%20Red%20Lanterns/Corybas%20dowlingii%20Red%20LanternsP1180804.JPG

This image of C. diemenica (syn Corybas diemenicus) is a good comparison. Note the difference between the stems.

Corybas demenicus

Corybas demenicus

2018 July Winning Photograph

1807 sm JF thelymitra azurea

Thelymitra azurea (common name Azure Sun Orchid)

With two sun orchids entered this month it is not surprising that one of them should be the winner which was John Fennell’s Thelymitra azurea a lovely blue flower with hints of pink. The other sun orchid taken by Pauline Meyers was one of the lovely pinks, T. rubra. She also entered a picture of Pyrorchis nigricans with a spider quietly waiting for its next meal! The final entry from Trevor Williams was that of a double headed Diplodium robustum which he found at Spring Gully Conservation Park.

 

June 2018 Winning Photograph

1806 sm JB T epipactoides1

 

An advantage of entering a photograph is that it does not need to be in season. This month John Fennell entered an autumn flowering Corunastylis fuscoviride and a late spring/early summer flowering Diuris sulpherea, Robert and Rosalie Lawrence both entered the winter flowering Diplodium robustum and the winning picture, John Badger’s Thelymitra epipactoides is an early spring flowering orchid.

Sun Orchids are another popular winner of the competitions and as there was a comprehensive article written on Thelymitra epipactiodes and as some have asked “what, actually, is a sun orchid?”, it is time to answer the general question about Sun Orchids.

Of all the Australian terrestrial orchids Thelymitra or Sun Orchid is the one that looks the least like an orchid as all the segments – the sepals and petals including the labellum – are very similar in appearance. They mimic the flowers of the Lilliaceae and Goodeniaceae families.

Nevertheless, it is an orchid as evidenced by the column. Columns are a unique feature of orchids. They are the combination of the reproductive organs into one structure. Between the different Thelymitra species, it is the column that is often the main distinguishing feature used in identification. Because, the column is quite detailed and so important in identification, we plan to feature this in future Journals.

Other general features of Thelymitra are single, non-hairy, mainly linear leaf (of course, there are always exceptions) with a single flower stem. Flowers range from being singular to having multiple flowers which come in a range of colours from yellow to pinks to blues. Despite the lack of nectar, most Thelymitra are bee pollinated but there are some that are self-pollinated. The pollinia instead of being yellow are white and it is not unusual to see the white pollen on the self-pollinating flowers.

Reference

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

Jones, D. L., A Complete Guide to Native Orchids of Australia Including the Island Territories. Reed New Holland

Jones, D. L.; Hopely, T; Duffy, S. M.; Richards, K. J.; Clements, M. A and Zhang X, Australian Orchid Genera an information and identification system. Electronic version, 2006, CSIRO

Thelymitra https://en.wikipedia.org/wiki/Thelymitra Accessed 4 July 2018