“The person who first records the whole pollination event will be very lucky indeed.” So wrote Bob Bates (South Australia’s Native Orchids, 2011). He was referring to the pollination event for Bearded Greenhoods in the genus Plumatichilos. As with many orchids there has always been a lot of conjecture about the pollination strategy involved so it is good to finally have photographic evidence of a previously unknown pollinator.
For several years now Rudie Kuiter, Mitchell Findlater-Smith and Rober Lindhe have been researching the relationship between orchids and insects, spending much time in the field observing and photographing the insects. Finally they have managed to obtain a photograph of a pollinator but it was not one of their photographs. Instead it was Neil Blair who took the photograph and observed a dagger fly pollinating a Plumatichilos. The male of these fascinating insects catches another insect and offers it for a nuptial gift to a female in order to be accepted as a mate. The photographs are amazing. It’s worth reading the paper Pollination of the Bearded Greenhoods (Orchidaceae) by Dagger Flies (Diptera: Empididae) just to see the pictures.
Each month the Native Orchid Society of South Australia has a special speaker. April’s speaker was Mark Bachmann from Glenelg Nature Trust. He spoke on the The Hydrological Restoration of Glenshera Swamp, Stipiturus Conservation Park.
At time of settlement swamps were common on the Fleurieu Peninsula but now they have almost all but disappeared. This has come about because of the clearing of land for farming beginning in the 1940s. There are now very few swamps left in the area. As a result in this region, the swamp orchids potentially face extinction.
BUT Mark’s talk was a good news story. In April, the Glenelg Nature Trust with the help of the Conservation Volunteers Australia (a Green Army program) began the work of reinstating the original creek by the judicious placing of regulating structures along the principal drain.
The good news is that the water returned as they were building the structures.
It was also a good news story because of the cooperation of different groups including a local land owner who was willing to have some of their land returned to swamp and no longer be available for their horses to graze.
We look forward to seeing the swamp refill and learning how the orchids respond.
Below are some of the orchids found at Stipiturus. Click on the images to go to the three articles documenting the work at Glenshera Swamp.
As part of 40th NOSSA anniversary, the theme for this month was Leptoceras menziesii (Hare Orchid or Rabbit Ears). Entries were received from John Badger, Pauline Meyers, Robert and Rosalie Lawrence, with John Badger’s being declared the winner.
In February 1978, it was announced that the nascent NOSSA society required an emblem. Members were invited to send in drawings, to be judged by members and then ratified by the committee. Mrs Chris Butler (Ron Robjohns’ daughter) was the winner. The first Leptoceras menziesii flowers to be benched at a NOSSA meeting were in September 1978. It appears to be an easy plant to grow but a most difficult one to flower.
This seems to be because it is fire dependent. In spring, it will flower profusely if there has been a summer fire such as occurred after the 2015 Sampson Flat (SA) fires. It is possible that the gas ethylene produced during a fire event may initiate the flowering response.
Otherwise, apart from the occasional flowering plant, it will be mainly leaves that are found when out in the field. The single leaf of this plant lying prostrate along the ground is distinctive. It is firm, boat-shaped, glabrous (no hairs), with a fine ‘snake-skin’ pattern. Interestingly, sterile plants can be mistaken for a plant with a developing bud as there will be at the leaf base a ligule (a thin membranous growth, often found on grass stems).
Reference
Backhouse, G, et al (2016) Bush Gems: A Guide to the Wild Orchids of Victoria Electronic version
Bates, R. J., ed. (2011). South Australian Native Orchids. Electronic version, 2011. NOSSA
So what do they look like? Amazingly Johann Georg Beer (1803 – 1873), an Austro-Hungarian orchidologist and explorer published in 1863 Beitra ¨ge zur Morphologie und Biologie der Familie der Orchideen. In it, Beer had produced in exquisite detail illustrations of orchid seeds. Beer was not the first to draw orchid seeds but his “drawings are morphologically accurate and artistically magnificent. Beer’s artistic ability, patience, and botanical expertise are obvious. His are probably the first detailed colour renditions of orchid seeds and seedlings to be published.”*
Reference
*Arditti, J, 2008, An history of orchid hybridization, seed germination and tissue culture, Botanical Journal of the Linnean Society June 2008
A common question asked is when to water terrestrials. The short answer is to keep them dry over summer but there are variations such as was previously posted about the watering regime for Chiloglottis. In the March 2017 NOSSA Journal, Les Nesbitt’s article highlights another watering variation.
Blue Tags
Les Nesbitt
Jane Higgs’ lovely pot of the red form of Pterostylis coccina in flower had a blue tag. Jane explained that a blue tag meant that watering had to commence in January for that pot and not at the end of February as is normal for most terrestrials. Start watering later and there will be no flowers. Her pots are under a solid roof. She explained that in the ANOS Vic cultural booklet (Cultivation of Australian Native Orchids) there is a list of cauline type greenhoods which she tags with blue, and includes Pterostylis decurva, aestiva, laxa, coccina, revoluta, reflexa, truncata, robusta, alata, and fischii. To this list can be added abrupta and also the rosette types ophioglossa and baptistii which shoot early.
I have trouble growing and flowering this group of Autumn flowering greenhoods. I went home and dragged out my ANOS Vic booklet and brushed up on the notes. I found several old blue labels in the shed and cut them into strips. I now have blue labels in my pots and the pots are grouped together in the shadehouse where they get afternoon shade. They were given a thorough watering but it will be too late to expect flowers this year. I find large tubers of this group rot easily in Spring and the plants go dormant earlier than other greenhoods. I will try to remember to move the pots under cover in September to let them dry off.
Diplodium robustum – one of the cauline greenhoods
Having a visual reminder would certainly make it easier to know when and which pots to water. Obviously other coloured tags can be used instead of blue, so long as they stand out from the label.
Previously we have posted about photographing orchids for identification – see here and here. But sometimes all that is desired is a beautiful picture of these exquisite flowers. Recently, March 21, 2017, National Geographic published just such an article titled How to Photograph an Orchid. Author Alexa Keefe relates some tips from German photographer Christian Ziegler. Needless to say half of the images featured are Australian orchids.
Below is a selection of some of the entries to NOSSA’s monthly picture competition.
The first competition for the year followed a wet orchid theme with three of the orchids being South Australian swamp orchids and the fourth from Western Australia; though not a swamp dweller, it grows in shallow moist soil.
The outstanding winner was Claire Chesson’s Cryptostylis subulata, followed by Robert Lawrence’s Spiranthes alticola, Rosalie Lawrence’s Pterostylis falcata and Pauline Meyer’s Thelymitra villosa.
Known to South Australian’s as the Moose Orchid, elsewhere it is either Large Tongue Orchid or Cow Orchid. This tall (40 to 110 cms) evergreen orchid is common in the eastern states where it is commonly found in damp areas as well as swamps. but in South Australia it is limited to swamps and is rated as endangered.
Whilst not an easy orchid to grow it has been cultivated although seed set has not always occurred. Helen Richards, an experienced Victorian terrestrial orchid grower, shared in an email how she grows them.
“Cryptostylis species grow from brittle rhizomes which can be quite long and they resent frequent disturbance. Mine are potted into a pot therefore that is large enough for the long roots and which will accommodate further growth for several years. My mix is ANOS basic mix, the same as I use for Pterostylis and many other genera. They need to be kept moist all year round, especially in summer when they flower and new leaves appear, their active growing period. I grow them in an area of moderate light. Others have seen pollinators active on the flowers but I haven’t. However seed capsules frequently develop without my assistance with a toothpick. Richard Thomson says they haven’t had success germinating the seed.”
I have recently been learning about propagating orchid via flasks but I have mould in some of the flasks.
Flask with orchid seeds and mould
There is mould in the flask with orchid seeds and also in the flask with Diuris tricolour in bulbs. The bulbs are almost ready for deflasking.
Flask of Diuris tricolour (no mould) – these will be deflasked later this year.
What can I do?
Answer:
With a home laboratory, no matter how careful one is, mould can still contaminate the jars of agar. If mould occurs when the orchids are still in seed, then the whole jar needs to be discarded. The seeds will not survive.
With the Diuris flask, as they are almost ready for deflasking, pot them out straight away. This needs to be done within 10 days of the mould appearing. The weather (March, 2017, South Australia) is still a little too warm but if left in the flask, the plants will die. Potting them out may give them a chance of survival.
When deflasking, it is important to rinse all the agar off the bulbs before potting on as normal. Once potted, it could help to cover the pot with a cut down clear drink bottle with the lid removed. This will allow some air to circulate. Keep the pot in a shady spot.
Potted Diuris tricolour with protecting bottle cover
Will it survive in the pot? Hopefully it might but at least the plants have a better chance of survival then if left in the flask where it would surely die.
Though Melbourne and Adelaide conditions are very different, in cultivation the watering is similar with the warning that in Adelaide it is a harsher environment for this genus.
The following information has been kindly supplied by Richard Thomson, an experienced terrestrial grower from ANOS Victoria.
Chiloglottis valida
Generally, Chiloglottis are kept damper than Pterostylis, during the dormant period. As many Chiloglottis need the potting media and the tubers dampening in summer, the general action with water, is to have the tubers damp until leaves emerge. Then to commence normal pot watering.
Chiloglottis, can get infected with rust. The first thing usually noticed is some pairs of leaves sticking up in the air. When you look closely you will notice some whitish little lumps on the underside of the leaf. Please immediately take the pot away from your other orchids as it is contagious across Chiloglottis. There does not seem to be an effective way to treat the infection.
ANOS VICTORIA MEETINGS
CHILOGLOTTIS
Species
State / Location
Month Benched
BUSH FLOWERING
WATERING
chlorantha
NSW
July Aug Sept
Sept to Oct
Keep damper from early February. Water when leaves emerge
cornuta
S NSW Vic Tas SA
Nov Dec
Nov to Feb – altitude
Keep damp all year. Water when shoots emerge.
diphylla
Qld NSW
Feb Mar Apr May Jun Jul Aug
Feb to May
mid to late January
sp affin diphylla
Feb
Keep damper from early February. Water when leaves emerge
formicifera
NSW
Jul Aug Sept Oct Nov
Aug to Nov
keep damper from early February, Water when leaves emerge
sp affin formicifera
Jul
Keep damper from early February. Water when leaves emerge
gammata
Tas high
Oct to Feb
jeanesii
Vic
Nov Dec
Nov to Jan
Keep damp all year. Water when shoots emerge.
longiclavata
N Qld
Feb Mar Apr May Jun Jul Aug
April to June
mid to late January
palachila
N NSW
Aug Sept Oct Nov
Nov to Feb
keep damper from early February, Water when leaves emerge
x pescottiana
NSW ACT Vic
Jun Jul Aug Sept Oct
Aug to Nov
keep damper from early February, Water when leaves emerge
platypetala
Sept
Keep damper from early February. Water when leaves emerge
platyptera
N NSW
Jul Aug Sept Oct
July to Oct
keep damper from early February, Water when leaves emerge
reflexa
NSW Vic Tas
Feb Mar Apr
Dec to May
mid January
sp affin reflexa
Feb
mid January
seminuda
S NSW
Feb Mar Apr May
Jan to April
keep damp all year
spyrnoides
S Qld N NSW
Feb Apr Dec
Dec to April
Keep damp all year. Water when shoots emerge.
sp affin spyrnoides
Feb Oct Nov Dec
Dec to Feb
Keep damp all year. Water when shoots emerge.
sylvestris
Qld NSW
Feb Mar Apr May Jun Jul Aug
Dec to May
early to mid January
trapiziformis
Qld to Tas
Jul Aug Sept Oct Nov
Aug to Nov
keep damper from early February, Water when leaves emerge
triceretops
Tas
Oct
Aug to Dec
Keep damp all year. Water when shoots emerge.
trilabra
NSW ACT Vic
Feb May Dec
Dec to March
late December or earlier
trullata
Qld
Jul Aug Sept Oct
Winter
keep damper from early February, Water when leaves emerge
truncata
S Qld
Jun Jul Aug Sept Oct
July to Sept
Early to mid February
sp affin truncata
Jul Aug Sept
Autumn
Keep damper from early February. Water when leaves emerge
vallida
NSW ACT Vic
Sept Oct Nov
Sept to Jan – altitude
Keep damp all year. Water when shoots emerge.
(As there is no January meeting, there is no information on flowering in cultivation for this month.)
From the chart, it can be seen that the cultivated flowering time does not always match the bush flowering time.
Leo Davis always has some interesting insights from his orchid observations. In this article he examines the position of the tepals (petals and sepals) in particular the Moose Orchid which he saw for the first time this year.
Have a close look, next season (winter to early summer) at some of our native lilies. Start with the jolly bulbine lily (Bulbine bulbosa), no longer a true lily incidentally, because it now resides in family Aspodelaceae, along with the grass trees. You will find three yellow petals at 12, 4 and 8 o’clock and closely behind them three almost identical sepals at 2, 6 and 10 o’clock, so at first sight you see six apparently identical tepals (sepals and petals). Move on to the rush fringe-lily (Thysanotus juncifolius), as described in Ann Prescott’s ‘It’s Blue With Five Petals’. Clive Chesson is more up to date and tells me it is now T. racemoides. Again it is no longer a true lily, now sitting in family Asparagaceae. Here the tepals are noticeably different. Three wide densely fringe edged petals will be found, if you view the flower face on, at 12, 4 and 8 o’clock. The narrow non fringed sepals sit close behind at 2, 6 and 10 o’clock. These are just a generalisations because if the flower turns only about 60o a sepal will be at the top.
Most orchids, while close relatives of the true lilies and the one time lilies, do not show these arrangements. Let’s start with some that do.
In the large duck orchid (Caleana major) the petal at 12 o’clock, the dorsal petal, is modified, as in most, but as usual, not all, orchids, to become a labellum. In this charmer the labellum takes the form of a duck’s head. Its function is to snap down trapping a pollinator insect in the cup shape column below it, forcing it into contact with the sticky off white stigma and/or the yellow pollinia below it. Look closely and you will find the other two narrow petals drooping at around 4 and 8 o’clock. Two folded, twisted sepals can be clearly seen at around 1 and 11 o’clock. The third sepal, at 6 o’clock, is tucked in behind the cup shaped column. Note that, as with lilies, the top tepal is a petal.
Caleana major, Knott Hill NFR Photographer: Leo Davis
The leek orchids (genus Prasophyllum) follow this pattern and also have their labellum at around 12 o’clock. These orchid groups, which are up the right way, are said to be ‘not upside down’, using the technical term ‘non resupinate’.
Most orchids are ‘upside down’ and are called resupinate. The whole flower rotates 180o, clockwise or anti I don’t know, at the embryonic stage. But let’s start with somewhat of an exception with the sun orchids (genus Thelymitra) which do not have a petal modified as a labellum. But they are indeed upside down.
Have a close look at the Thelymitra benthamiana flower. Note that the three petals, at roughly 2, 6 and 10 o’clock, are in front of the three slightly larger but very similar sepals, at 12, 4 and 8 o’clock.
Note that the toptepal is a sepal. The flower is upside down, that is resupinate. In most orchids the petal at 6 o’clock would be modified to be a labellum.
Thelymitra benthamiana, Scott Creek CP; Photographer: Leo Davis
The Arachnorchis (possibly Caladenia to you) stricta, from Sherlock, out in the mallee, is more typical of terrestrial orchids in SA. It is upside down, that is resupinate, and has a petal modified to be a labellum.
The bottom petal has become a wide labellum, with fine edge combs and parallel rows of rich plum coloured calli covering its centre. Out at roughly 3 o’clock is a narrow petal, the other invisible on the other side. At the top, pressed tightly against the column, a sepal arches forward. Two larger sepals extend down at around 5 and 7 o’clock.
Arachnorchis stricta, Sherlock; Photographer: Leo Davis
When I saw my first, my only, moose orchid, this season, I was in such a state of excitement that it looked to me to be up the right way, that is to say upside down.
Cryptostylis subulata, Stipiturus CP; Photographer: Leo Davis
Have a look. Two narrow short roughly vertical petals at about 1 and 11 o’clock. There are two sepals at just past 3 and just before 9 o’clock. That’s OK but where is the other sepal? Are there it is, where it should be, at midday. But hang on, it’s behind the flower stem (peduncle) and where is the column?
Cyrtostylis subulata with labellum lifted; Photographer: Leo Davis
Holding the labellum up with a stick I found the column, the stigma and the pollinia, underneath the labellum. The third sepal now appears to be at 6 o’clock. And it all became clear. This flower was up the right way (non resupinate) but it has turned forward, on its peduncle, by about 180o, to become upside down, but not in the manner of resupinate flowers, because it is back to front. It is an inverted non resupinate flower. Still with me?
NOSSA 