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.

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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

March 2018 Winning Photograph

1803 A4 sm JF Arachnorchis formosa

Four very different species were entered this month. Ricky Egel’s autumn flowering Coryunastylis fuscoviridis (see February Journal for name usage), Rosalie Lawrence’s winter flowering Diplodium bryophilum and John Fennell’s spring flowering Stegostyla cucullata and Arachnorchis formosa.

It was no surprise that John’s A. formosa (syn. Caladenia formosa) was the winning photograph. Words such as stunning, spectacular, wonderful and attractive are used in the description of this rare orchid and is reflected in its common names – Scarlet Spider Orchid, Elegant Red Spider Orchid, Elegant Spider Orchid and Blood-red Spider Orchid. It is truly a stunning red flower with its drooping petals and sepals (tepals).

A. formosa is part of the large patersonii alliance which is characterised by white to reddish flowers with (mainly) drooping tepals ending in long, slender (sometimes thickened) sparsely to densely glandular (hairy) tails, labellum with short to long marginal teeth. The features that separate A. formosa from others in the complex are the large (~60 mm across) deep red flowers with long (~80mm) tapering, drooping tepals. Similar species to A. formosa is the smaller once common but now extremely rare Caladenia ‘Fleurieu Peninsula’ In Victoria there are some other similar species.

A. formosa is confined mainly to the South East and into south western Victoria.

References:

Backhouse, G., (2011). Spider-orchids – the Genus Caladenia and its Relatives in Australia, Melbourne, Electronic version.

Backhouse, G., et al, (2016). Bush Gems: A Guide to the Wild Orchids of Victoria, Australia, Electronic version.

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

2017 June Winning Picture

1706 sm RWL Thelymitra grandiflora 10

This month’s theme for the photo competition was blue and white. White flowers can occur as a result of lack of colour such as Rosalie Lawrence’s Caladenia latifolia (Pink Fairies) which is normally pink. White orchids can also occur naturally such as the Arachnorchis argocalla (White Beauty Spider Orchid) and Arachnorchis intuta (Ghost Spider Orchid) both photographed by John Fennel, or as a dominant colour such as Lorraine Badger’s Eriochilus collinius (syn Eriochilus sp Hills Woodland).

Of the blue orchids, both Ricky Egel and John Badger entered pictures of Thelymitra x truncata (Blue Spotted Hybrid Sun Orchid) whilst Robert Lawrence entered a Thelymitra grandiflora (Giant Sun Orchid) which was the outstanding winning picture.

Blue in the floral world is unusual colour in the floral world for it is not a naturally occurring colour. In fact, “[t}he key ingredient for making blue flowers are the red anthocyanin pigments. Less than 10 percent of the 280,000 species of flowering plants produce blue flowers.” (Lee, 2010 as cited in Oder 2014).

Whilst blue orchids occur outside of Australia, their “colour cannot rival” … “the intensely blue flowers” … “especially [are] unique in the orchid world” … “of their Australian counterparts. The sun orchids (Thelymitra) in particular are famous for their sky blue flowers.” (Ronse 2008: 103)

Based upon Jones 2006 tome, the following genera have true blue orchid species – Cyanicula (9 species), Pheladenia (1 species), Epiblema (1 species) and the largest group Thelymitra (about 65 out of potentially 118 species) plus one hybrid, XGlossodenia tutelata. Of the epiphytes, blue is almost non-existent except for three which Jones lists that rarely might be bluish and they are Vappodes bigibba, V. lithocola and V. phalaenopsis*.

With such rarity, is it any wonder then that the Chinese attached special significance to it as a plant that could cure lung disease and the Aztecs saw it as a symbol of strength.

*Names used as they appear in Jones 2006 tome

Reference

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

Lee, David (2010), Nature’s Palette: The Science of Plant Color< Chicago, University of Chicago Press

Oder, T, The Science of Blue Flowers https://www.mnn.com/your-home/organic-farming-gardening/stories/the-science-of-blue-flowers accessed 6 July 2017

Pretty Zesty All About Blue Orchids http://www.prettyzesty.com/2012/11/all-about-blue-orchids.html accessed 6 July 2017

Pterostylis Pollinators

Rudie Kuiter et al have been observing orchid pollinators over many seasons spending hours watching and becoming familiar with pollinator interaction with the orchid, learning when to anticipate pollination activity.

Their observations of various Pterostylis species has been documented in Overview of Pterostylis Pollination (Orchidaceae) in Victoria. In all, they observed 53 Pterostylis species and 40 species of pollinators from several different genera. They noted that some pollinators species were active most of the day but others were only active in the late afternoon whilst others were “only seen on dusk and possibly are nocturnal as well”.

 

 

2017 May Winning Picture

Corunastylis morrisii @ Simpson 25/2/2017

May’s theme was miniscule, or less than 10mm. Of the eight entries five were Corunastylis, two Spider orchids from Western Australia and one an epiphyte. The flowers of the two spiders, Caladenia pachychila (photographer Rob & Jenny Pauley) and Caladenia bryceana subsp. bryceana (Pauline Myers) were the largest of the group being about 10mm across whilst the Bulbophylum globuliforme (Ros Miller) and C. despectans (Rosalie Lawrence) were the smallest being only 2mm across.

Of the remaining Corunastyllis entries the flower size ranged from 3mm for C. pumila (Rob & Jenny Pauley), 4mm for C. tepperi (Ricky Egel), 7mm for C. ciliata (Rosalie Lawrence) and 8mm for C. morrisii (Rob & Jenny Pauley).

The winning picture C. morrisii (Bearded or Hairy Midge Orchid) is one of the larger midge orchids. Other synonyms are Prasophyllum morrisii and Genoplesium morrisii. This common species is mainly found in Victoria but it does extend into southern New South Wales in the east and in the west just spills 50 km over the border into South Australia where it is rated endangered. It also occurs in the south east of Tasmania.

Flowering Times: Nov – May

 
 State N D J F M A M
Tas        
NSW      
Vic
SA          √

With such a wide distribution range, it is not surprising to see quite a variation in flowering time from late spring through to autumn depending upon location.

Reference

http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Genoplesium~morrisii

https://en.wikipedia.org/wiki/Caladenia_pachychila

https://en.wikipedia.org/wiki/Caladenia_bryceana_subsp._cracens

http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Genoplesium~pumilum

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

Wapstra, M., Roberts, N., Wapstra, H. & Wapstra, A. (2012). Flowering Times of Tasmanian Orchids: A Practical Guide for Field Botanists. Self-published by the authors (May 2012
version).

Backhouse, G., Kosky, B., Rouse, D. & Turner, J. (2016). Bush Gems: A Guide to the Wild Orchids of Victoria. Self-published by the authors

2017 April Winning Picture

1704 LN Diuris behrii sm

April’s theme was yellow and orange. All of the entries proved to be spring flowering. There were several Diuris. Claire Chesson, Rob Pauley and John Fennel all entered D. orientis; Les Nesbitt and Rob Pauley D. behrii and Pauline Meyer D. corymbosa from Western Australia. Pauline also entered Caladenia caesaria subsp. maritima and John Thelymitra benthamiana.

The winning picture was Les Nesbitt’s D. behrii (Cowslip Orchid) which occurs in Victoria, New South Wales, Australian Capital Territory whilst in South Australia it is rated as vulnerable.

Les Nesbitt has been working on a recovery project of these orchids for Hillgrove Resource’s flagship, the Kanmantoo Copper Mine, located almost 55 KM from Adelaide. As this orchid is often mentioned in NOSSA Journals, it might be worthwhile looking at the person after whom this species was named.

First collected by German born Dr Hans Herman Behr (1818 – 1904) who first visited* South Australia in 1844 when the colony was barely 8 years old. During his two years in South Australia he became the first person to systematically study our botany and entomology sending reports and samples back home. The results of his observations were published in various journals, and many of his collections were named and described by other botanists including his friend, Diedreich von Schlechtendal (1794 – 1866) who named Diuris behrii after Hans.

Hans Behr was an interesting man. A man of many aptitudes; medical doctor, entomologist, anthropologist, botanist, duellist, socialist, poet, novelist, linguist, member of the Bohemian Club of San Francisco and a man of wit. From the many reminiscences written about him, it would appear that he was a likeable gentleman and a generous teacher.

Unfortunately, not everyone liked him because “he was a sworn enemy of all scientific humbug, of quacks and false pretenders” and “he never refrained from expressing his opinion of them, quite regardless of person or station” but his humour shone forth in dealing with them. Once he named a “particularly obnoxious louse” after one of his enemies.

Behr revisited South Australia in 1848 during which time he became acquainted with German-Australian botanist, Ferdinand von Meuller. He maintained friendship with many of the scientific men of the time including Ferdinand Mueller and it was through this friendship that many Australian plants were introduced into California where Behr later settled after his travels.

Though the study of butterflies was his first and enduring love, he is remembered and honoured in Australia for his botanical interests. Of the twenty-two plants named after Behr, two are orchids: Diuris behrii and Arachnorchis behrii (synonym Caladenia behrii).

*The Journal incorrectly stated that he visited South Australia with his friend, Diedreich von Schlechtendal. This did not happen. As far as I am aware Schlechtendal did not visit South Australia.

Reference

https://archive.org/details/doctorhansherman00cali

https://archive.org/stream/jstor-1630874/1630874_djvu.txt

https://en.wikipedia.org/wiki/Hans_Hermann_Behr

https://www.anbg.gov.au/biography/behr-hermann.html

Kraehenbuehl, D. N., Dr HH Behr’s Two Visits to South Australia in 1844-45 and 1848-49, J. Adelaide Bot. Gard. 3(1): 101 – 123 (1981)

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

2017 March Winning Picture

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.

1703 sm JB Leptoceras menziesii

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

Lawrence, R. W., (2011) Start With The Leaves

NOSSA Journal Volume 2 No 6 July 1978

NOSSA Journal Volume 2 No 9 October 1978

Born to Fly …

Orchid seeds are minute …

… like dust particles.

Orchid seeds are produced in the thousands …

… like dust particles.

And like dust,

Orchid seeds are born to …

… FLY!

 

OLYMPUS DIGITAL CAMERA

Dust-like seeds of Pterostylis nutans

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.”*

Fig-1-Orchid-seeds-Beer-1863

Seeds_of_orchids_(J.G.Beer_-1863)

Reference

*Arditti, J, 2008, An history of orchid hybridization, seed germination and tissue culture, Botanical Journal of the Linnean Society June 2008

https://www.researchgate.net/publication/229790264_An_history_of_orchid_hybridization_seed_germination_and_tissue_culture