Tracking Down the elusive Prasophyllum suttonii

Rudie Kuiter’s Short Paper 2 Taxonomic Status of the Mauve Leek-orchid Prasophyllum suttonii Rogers & Rees, 1912 (Orchidaceae) published in May 2017 documents how he used original source material to determine the identification of a species that was considered extinct.  Prasophyllum suttonii belongs to the Prasophyllum odoratum/diversiflorum complex and is very similar to the later named Prasophyllum alpestre. It was considered to be extinct but Rudie’s view was not that it was extinct but that it had been “lost in taxonomy, and its status need to be restored”. His article documents how he used original material to help determine identification of the species he had photographed.

In his summary Rudie has some good advice about how to effectively use the material available –

  • Use original descriptions and illustrations
    • Original descriptions are preferred over type specimens
    • later descriptions may be based upon second hand information which may or may not be accurate.
  • Drawings have some value but depend
    • upon the skill of the artist to show the crucial details
    • upon whether they were drawings from fresh or preserved specimens
  • A good photograph will be better than a drawing
  • Type material is useful but may deteriorate over time

Images from Rudie Kuiter's article on Prasophyllum suttonii

 

Click here to read the complete article

 

Growing Leek Orchids – Is it Possible?

The Native Orchid Society of SA has been involved with the Threatened Orchid Project which is attempting to propagate some of our most threatened orchids.  There has been some success such as Thelymitra epicaptoides (Metallic Sun Orchids) but others are proving elusive.  Marc Freestone, from the Orchid Conservation Project, Royal Botanic Gardens Victoria, is a PhD student who is researching one such difficult to grow orchid genus, the Prasophyllum.

Prasophyllum murfettii sm
Prasophyllum murfettii (Denzel’s Leek Orchid)

To assist with his research Marc has the sent the following request.

CAN ANYONE GROW LEEK ORCHIDS?

South Australia has about 40 species and Victoria about 74 species of the native Leek Orchids, Prasophyllum.  Some are on the brink of extinction.

A major problem hampering efforts to prevent our Leek Orchids from going extinct is that they have proven next to impossible to grow in cultivation.  They have proved extremely difficult, usually not germinating at all, or germinating but then dying soon after.  Occasionally some success has been had (particularly with symbiotic germination) but successful germination trials to our knowledge have so far proved un-repeatable.  Working out how to grow Prasophyllum is critical for the survival of many species at risk of extinction across southern Australia.

To try and change this, I will be studying Prasophyllum and their relationships with symbiotic mycorrhizal fungi.

But I need your help!

I am wanting to hear from as many people as possible who

  • have tried (either successfully or unsuccessfully) to grow Leek Orchids or the closely related Midge Orchids (Corunastylis).
  • have observed Leek Orchids (or Midge Orchids) recruiting from seed in the wild.

If you can help, or know of anyone who might be worth talking to, please contact me at: marc.freestone@rbg.vic.gov.au or 0428 304 299.

(Funding and support for this project: Australian National University, Federal Government National Environmental Science Programme, Royal Botanic Gardens Victoria, University of Tasmania).

I would encourage people to contact Marc with whatever information that you have, no matter how insignificant you may think it is.  Every little bit helps including unsuccessful attempts.

His eventual aim is to be able to work out how to grow them reliably from seed in cultivation.

Genes, seasonal conditions or pure chance?

Leo Davis is an orchid hunter.  He is meticulous in his observations and notes details that many of us may miss.  In this article he muses upon the variations that he sees in the field.

You, as I do, must occasionally come upon an orchid or an orchid event that is a little outside normal experience.  When I do, I wonder whether this is a purely chance event or is it caused by recent local environmental factors, or is it due to the genes of the plants.  Or a combination of these?

I’ve been watching a couple of patches of fire orchids (Pyrorchis nigricans) that many of you will be familiar with, one at Knott Hill N.F.R., the other at Monarto C.P., where a few plants flower every year, without the normally required stimulation by fire.  I need to check whether it is the same plants that flower each year.

Pyrorchis nigricans.jpg
Pyrorchis nigricans (Fire or Undertaker Orchid) Photo: Leo Davis

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The tall leek orchid (Prasophyllum elatum) puts up leaves at Scott Creek C.P. every year but does not flower. A fire swept through in early 2014 and most plants flowered in October.  They’ve not flowered since.  But over at Ramsay Way, west of Pt. Vincent, a few plants flower each year without fire.  I assume genes are involved.

Prasophyllum elatum
Prasophyllum elatum (Tall Leek Orchid) Photo: Leo Davis

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In April 2014 I chanced upon a patch of Adelaide Hills parson’s bands (Eriochilus collinus), along Moore’s Road, at Morialta C.P., in which the majority of plants had three flowers per stem. Was this because of favourable conditions or genes? Over the next two seasons I saw only the occasional double header and mainly single flowered plants. I will continue observations and records.   

 Eriochilus collinus

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In July 2015 I found a dense patch, about 3 m2 in area, of hundreds the common mallee shell orchid (Diplodium dolichochilum), in Ferries-McDonald C.P. As usual less than ten plants were in flower, but two of them were double headers.  I’ll be checking this season and expect this not to be a chance event but one due to genes.

Diplodium dolichochilum
Diplodium dolichochilum syn. Pterostylis dolichochila (Slim Tongued Shell or Common Mallee Shell Orchid) Photo: Leo Davis

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On May 27, 2012, Bob Bates led a NOSSA outing to Scott Creek C.P. and as ever, when he leads, we saw and learned a lot.  He showed us a patch of fringed hare-orchids (Leporella fimbriata) that he assured us should not be growing there on that steep rocky site and that the plants would not flower most years.  Unfortunately he was right, as usual.   I could not find plants in 2013 and 2014 and it took three searches in 2015 to find a very few leaves. On May 10 this year, over an area of less than 10 m2, I found perhaps 50 leaves and just seven plants in flower.  Three of these had three flowers and a tiny unopened bud (check the photo) and the others were doubles.  I’ve never seen a triple flowered plant in hundreds I’ve seen at Knott Hill N.F.R.  Are genes in an isolated population at play here?  Given the paucity of flowering at this site, it may take me years to sort this one out.

Leporella fimbriata
Leporella fimbriata (Fringed Hare  or Ballerina Orchid) Photo: Leo Davis

Leo Davis.

 

CLUES TO ORCHID IDENTIFICATION – Prasophyllum & Microtis Leaves

Orchids are attractive and abound in variety. It is the variety that often provides the challenge of identification. As a novice it can be a bit overwhelming. In the eye of the beginner, the experienced orchid hunters appear to have no difficulty with identification. Over the years they have accumulated various clues that guide them toward accurate identification.

This series aims to document the clues that orchid hunters use.

Prasophyllum and Microtis Leaves

The first in the series relates to distinguishing between Microtis and Prasophyllum leaves. When in flower it is easy to see which is which but not so when only in leaf; and as they do not always produce flowers it is helpful to be able to separate them out at leaf stage.

Both leaves are green. Both are cylindrical. Both are hollow. Both resemble onion leaves.

M & P Leaves
Both types of leaves are long, thin and green.  The damaged Microtis leaf (below) shows the hollow.

The differences can be found in one or two areas. Microtis leaves are always green at the base whereas Prasophyllum leaves usually but not always will have a red or purplish coloured base. To help in identification, it is necessary to examine the base by moving the leaf litter aside to see where the plant emerges from the soil.

M & P Leaf Bases
The bases reveal the difference between the two genera.

Prasophyllum species that could have a green base are P. laxum, P. occulatans, P. sp Jip Jip, P. elatum, P. sp Sandplain, P. pallidum (although this is short and usually in bud when noticed), P. spicatum, P validum.  So further observations are necessary.

Another other area of difference is that the broken leaf of a Microtis yields a mucilaginous (thick sticky) sap; the Prasophyllum leaf does not.

Within the segregate genera used by many NOSSA members, there are two other genera with similar leaves. They are Microtidium and Hydrorchis. Again they are green, cylindrical, hollow but only hollow in the lower half. The top half is solid.

It should also be noted that Microtis can form dense colonies but Prasophyllum will never form more than loose colonies.

Finally, if upon gently feeling the base of these leaves it feels solid, that will indicate that there is a bud and it will most likely flower this season.

M & P Flowers
Once in flower, the differences between the two genera is obvious.

Australian Orchids & the Doctors they Commemorate Part 15 of 20

Charles Stanford Sutton (1895 – 1950)

A Melbourne general medical practitioner and expert on subalpine flora.

Orchids

Pterostylis suttonii  Name not found in the Australian Plant Name Index or International Plant Index
Prasophyllum suttonii or Mauve Leek Orchid