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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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

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

May 2018 Winning Photograph

One never knows what species will be entered each month – this month’s entries included Andrew Primer’s Eriochilus collinus, John Fennell’s Prasophyllum elatum, Marg Paech’s Pterostylis nutans and the winning picture, Pauline Meyer’s Arachnorchis sp. (which has subsequently been identified as Arachnorchis sp.)

 

1805 sm PM Arachnorchis sp

In the last six years there have been over a dozen photo competition articles (the most recent April 2018) written on some aspects related to Spider Orchids. So, with another Spider Orchid winning the competition it is about time to answer the question – What Is A Spider Orchid?

 

Around the world, the common name Spider Orchid has been bestowed upon a number of orchids in different genera. In Australia, they have principally been applied to a large group within the genus Caladenia, a highly diverse cumbersome genus.

Caladenia in the broad sense is distinguished by erect flower stem and single linear, ovate to lanceolate leaf, (both hairy), labellum distinctly different from the other segments, generally fringed, curved and decorative calli. But within this genus it has been recognised for a long time that there are several distinct but varied groups, which has been reflected in the common names – Dragon, Pink Fingers, Hare, Spider, Wispy Spider, etc.

Consequently in 2001, several segregate genera were published including Arachnorchis for the common named Spider Orchids. This was not widely accepted, as reflected by the Herbaria of Australia. Indeed the original authors are no longer using the segregate names.

Yet despite all that, the segregate names have proved to be very practical for fieldwork. By using the segregate name when species is unknown, extra information is communicated. This was the case with Pauline’s picture. Yes she photographed a Caladenia but which one? It was an Arachnorchis species.

With that in mind, it is time to consider the features that make up a Spider Orchid or Arachnorchis.

In following through a dichotomous key Arachnorchis is immediately separated out from the rest of the Caladenia by the presence of two yellow waxy glands at the base of the column. As this is not the immediate feature seen, the following chart comparing it with the very similar looking Joneseopsis should assist with recognising some of the main distinguishing features.

  SPIDER ORCHIDS
(ARACHNORCHIS)
WISPY SPIDER OR DADDY LONG LEGS
(JONESIOPSIS)
Leaf Sparse to densely hairy
Narrow to broad lanceolate
Red base
Sparsely hairy
Slender
Red base
Stem Wiry densely hairy Hairy wiry
Flower    
Dorsal sepal Erect Erect
Tepals

(Petals & Sepals)

Long & slender with long slender glandular tails or thickened short to long clubs*

Petals and sepals similar size

Narrow, end in very long thin threadlike glandular tails*
Labellum Trilobed
obliquely erect lateral lobes
Midlobe often differently coloured to the base
Small indistinctly lobed

Narrow

  Hinged Hinged
Apex Rolled under at the apex Rolls under*
Margins Fringed with short to long teeth* Short, blunt teeth to smooth
Calli Vary from short rounded crowded to long curved and widely spaced Short blunt congested lamina calli*
  2 or more rows 2 rows*
Basal Gland 2 yellow at  base of the column None
Growth Habit Loose groups* Clumping

 

*Exceptions in all these descriptions

1805 PM Arachnorchis sp Labelled wm

Labelled Features of a Spider Orchid

Reference

Backhouse, G, (2018) Spider Orchids: The Genus Caladenia and Its Relatives in Australia ISBN: 978-0-9946489 Electronic version

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

 

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

Banded Greenhoods Bundled Together

Here in South Australia we often have only one or two species of a complex or a genus but this is not necessarily the case in the rest of the country. One such instance is Urochilus sanguineus (syn Pterostylis sanguinea) or Maroon Banded Greenhood. It is possible that we may have a subspecies or possibly the Mallee form but nothing like the occurrence of  this species in Western Australia where it is but one of many in a complex of several – the Pterostylis vittata complex or Banded Greenhoods*.

Below, with permission, is Andrew Brown’s post on Facebook with notes and images about the complex as it is understood in Western Australia.

The Banded Greenhood complex in Western Australia

Members of this complex grow 150 to 450 mm high and have up to 20 green, brown or reddish-brown white banded flowers characterised by their, short, broad lateral sepals which are joined at the base and a small, insect-like labellum which flicks up when touched. In all species, flowering plants lack a basal rosette of leaves while non-flowering plants have a flattened, ground hugging, rosette of leaves.

Banded greenhoods are found over a wide geographic range between Binnu north of Geraldton and Eyre on the Great Australia Bight, growing in shrublands, woodlands, forests and shallow soil pockets on granite outcrops.

There are ten Western Australian species in this complex, seven of which are formally named. However, as two were named as species of Urochilus, a genus not recognised in Western Australia, only five of these names are currently recognised here. In Western Australia, all members of the complex are considered to be in the genus Pterostylis.

All are winter flowering.

Pterostylis concava

Pterostylis concava AB

Distinguished from other members of the complex by its prominently cupped lateral sepals and the upturned projection near the base of the labellum. Found between Bindoon and Mt Barker.

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Pterostylis crebriflora

Pterostylis crebriflora AB.jpg

Distinguished from the similar Pterostylis sanguinea by its often shorter stature and slightly larger flowers which are crowded in a dense spike near the top of the stem. Found on the Darling Scarp near Perth.

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Pterostylis sanguinea

Pterostylis sanguinea AB.jpg

A very common species that is also found in South Australia, Tasmania and Victoria. It was named from specimens collected in South Australia. The species is similar to Pterostylis crebriflora but is usually taller with smaller, more widely spaced flowers. Flower colour is variable and it is not uncommon to find brown and green flowered forms growing alongside one another. Found over a wide area between Mullewa and Eyre on the Great Australian Bight.

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Pterostylis sanguinea (Mallee form)

Pterostylis sanguinea mallee form AB.jpg

An unnamed member of the complex distinguished from Pterostylis sanguinea by its short stature and few flowered inflorescence. Found over a wide range from the Stirling Range to the north of Esperance.

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Pterostylis sp. Coastal

Pterostylis sp coastal AB.jpg

Some consider this to be a form of Pterostylis sp. small bands but it is usually taller with more widely spaced flowers. The sepals are also narrower and often slightly cupped. Found mostly in near coastal areas between Dongara and Bunbury. Similar looking plants have also been found further inland between Brookton and Mt Barker.

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Pterostylis sanguinea (green flowered form)

Pterostylis sanguinea green flowered form AB.jpg

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Pterostylis sargentii

Pterostylis sargentii AB

A common, widespread species, distinguished from other members of the complex by its smaller flowers and fleshy, tri-lobed, frog-like labellum. Found over a huge geographic range between Northampton and Mt Ney, north of Esperance.

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Pterostylis sp. Crowded

Pterostylis sp crowded AB

 

A widespread species named Urochilus atrosanguineus in June 2017. Distinguished from the similar Pterostylis sanguinea by its more robust habit and larger dark reddish-brown flowers. It is also similar to Pterostylis crebriflora but generally flowers earlier and has more widely spaced flowers in a longer spike. Found between Wongan Hills and Katanning with rare, scattered populations on the Swan Coastal Plain.

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Pterostylis sp. Eyre

Pterostylis sp Eyre AB

A distinctive member of the complex distinguished from others by its pale coloured flowers. Like Pterostylis sanguinea (mallee form) it has a short stature and few flowered inflorescence. Found along the coast between Toolinna Cove and Eyre on the on the Great Australian Bight.

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Pterostylis sp. small bands

Pterostylis sp small bands AB

A northern species named Urochilus orbiculatus in June 2017. It is regarded by some researchers to be a form of Pterostylis sp. coastal but is usually shorter with a more densely crowded spike of flowers. Its sepals are also broader, more rounded and flattened rather than slightly cupped. Found north of Perth between Cataby and Binnu.

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Pterostylis vittata

Pterostylis vittata AB.jpg

A widespread species distinguished from other members of the complex by its less fleshy, paler coloured, predominantly green flowers and narrower, elongated, slightly cupped sepals. The flowers also have a more translucent appearance. The typical form is found between Bindoon and Balladonia. There is a northern form with a shorter spike of often fawn coloured flowers found between Cataby and Binnu.

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It should be noted that in South Australia and Victoria U. sanguineus was originally called P. vittata but that species is now recognised as being endemic to Western Australia.

*As an aside, the common name Banded Greenhoods is used in South Australia for the subgenus Bunochilus (previously Pterostylis longifolia which is now considered endemic to New South Wales).

 

Spiranthes alticola

At this time of the year there are not many orchids flowering in South Australia but one that is just finishing is Spiranthes alticola. The genus Spiranthes, commonly known as Ladies Tresses, is found throughout Australia, Eurasisa and the Americas.The following description is an extract from South Australia’s Native Orchids 2011 DVD which is available from the Native Orchid Society of South Australi. 

Spiranthes alticola D.L.Jones

Swamp Spiral Orchid

Etymology: The name alticola means high dweller, referring to its distribution in Eastern Australia, in west Victoria and South Australia’s South East.  It also grows near sea level.

Synonyms: Previously included in Neottia australis R. Br., S. sinensis (Pers.) Ames and S. australis R.Br.

 

 

(These two pictures show the variation in colour.)

Description: Leaves 3-5, narrow lanceolate, shiny, erect at the base, to 15 cm long. Flower stem to 45 cm tall, slender, flexible, with several sheathing bracts.  The flowers are numerous in a dense spiral, pink with a white labellum, rarely all white.  Segments are 6-10 mm long, sepals somewhat triangular, petals lanceolate, together forming a short tube, the tips free and recurved, and the lateral sepals divergent.  Labellum with a broad, decurved crisped, pellucid mid-lobe, side-lobes erect small.  The flowers are faintly fragrant.

spiranthes-alticola-leavesrwl-92

(Leaves of Spiranthes alticola)

Flowering: Dec – Jan – Feb.

Similar Species: S. australis, S. sp. Late selfing-white.

Distribution: SL, KIx, SE; NSW, Vic, Tas.

Confined in South Australia to a few high rainfall, near coastal, often mountain locations, southward from the Adelaide Hills in the Southern Lofty region, extinct on Kangaroo Island, (one record only), and South East; also in New South Wales, Victoria and Tasmania.

Habitat: Restricted to peaty bogs and swampy creek-sides, often in locations that are inundated throughout winter; in some areas surviving in paddocks grazed by stock.

Distinguishing Features:  S. australis, which is from the eastern states and is not strictly a swamp plant, has smaller darker pink flowers with a narrow labellum.

  • The two South Australian forms treated here are regarded as distinct species as where they are sympatric they begin flowering at different times and do not intergrade. S. alticola is the more delicate of the two.

Notes:  The best specimens are found on mowed firebreaks adjacent to swamps.  When vegetative reproduction produces two clonal plants next to each other the spiral arrangement of one is often a mirror image of the other.  See Gallery.

Native bee pollinators work the spikes from the bottom upward but as the stigma becomes receptive well after the pollinia have matured this mechanism helps ensure outcrossing.

Plants do well in cultivation if kept moist over summer.

Conservation Status:

Status in Legislation: Not listed nationally, rare in South Australia.

Suggested Status: Rare in South Australia but more common in the Eastern States

 

Mad Dogs and …. Orchidologists

Mad dogs and Englishmen are not the only ones to go out in the  midday sun.  For orchidologists to see Sun Orchids flowering, then it is out into the midday sun on a hot day because that is when they open.  There is no point going much before 11am and by 2pm most are closing and no point going out on a cool or windy day.

1604 sm CC T benthamaniana

But for those who don’t want to  go out (or cannot get out) into the midday sun, here is a video to be viewed in the cool of the shade.

This video features the Leopard Sun Orchid (Thelymitra benthamiana) an uncommon Sun Orchid in South Australia.  Unlike many sun orchids which requires a view of the flower to confirm identification, this one can be identified by the leaf alone.  At the beginning of the video take note of its distinctive leaf.

Thelymitra benthamiana

Pterostylis plumosa: Plumatochilos plumosum

plumatochilos-sp-woodland-sm

Plumatochilos sp Woodland

 

If you are out and about this week, keep an eye out for this attractive and unusual greenhood with its bottle brush labellum and rosette of “pineapple” like leaves.

Commonly known as Woodland Plumed or Bearded Greenhood, or Plumatochilos sp. Woodland Bearded Greenhood.  The reason for the phrase name is because many consider that it is a separate species, in this instance, from Plumatochilos plumosum (syn Pterostylis plumosa).  Originally all of the Bearded Greenhood were considered as one species – Pterostylis barbata but then Leo Cady named Pterostylis plumosa as a separate species.  David Jones in his 2006 tome listed four species, P. barbatum, P plumosum, P. tasmanicum and P. turfosum.

Here in South Australia, Bates lists P. tasmanicum and two with phrase names suggesting that they are distinct from P. plumosum.

Peter Fehre recently posted on the Tasmanian Native Orchids Facebook page some helpful hints differentiating between P. tasmanicum and P. plumosum.  Very similar information is found in Bates South Australia’s Native Orchids.  These differences are:

P. tasmanicum – a short plant: short flower stem (not more than 14 cms), short labellum (to 15mm) , short ovary; short blunted galea (hood) to 25mm.  It prefers damp, sandy areas and swamp margins.

P. plumosumhas length; long flower stem (10 – 30 cm), galea to 40mm with a long tip, long labellum (to 25mm).  It is a plant of the woodlands and forests growing on well drained soil.

The differences between the two phrase named species are more subtle

References:

R J Bates, 2011, South Australia’s Native Orchids DVD, NOSSA

D L Jones , 2006, A Complete Guide to Native Orchids of Australia