Another Greenhood

Recently after writing about Nodding Greenhoods I was alerted to another Pterostylis now flowering locally, the Striated Greenhood Pterostylis alata. Kate Sandiford kindly pointed me in the right direction and I found this small colony at Strangways.

Striped Greenhoods, Strangways, 13th July 2011

I find identification of many orchids pretty difficult – this species is somewhat similar to the Autumn Greenhood P.revoluta [see post April 15th 2011], but more petite, less finely marked and flowers later. The Greenhoods seem to be a taxonomic ‘minefield’, with recent revisions splitting them into a number of related genera … thankfully bird identification is much more straightforward!

Colony of Striped Greenhoods, Strangways, 13th July 2011

Erratum: These plants have subsequently identified as Large Striped Greenhood Pterostylis robusta [see post]

10 responses to “Another Greenhood

  1. Geoff, I think you will find that the orchid is the Large Striped Greenhood, Pterostylus robusta, not Stroped Greenhood, P. alata. I checked Backhouse and Jeanes The Orchids of Victoria, first published 1995, but I’m pretty sure the names are still the same. P. robusta is alsoa known as the Sharp Leaf Greenhood and Green Shell Orchid. We’ve (Castlemaine Field Nats) know of them from a spot on Captains Gully Road,

  2. Kate Sandiford

    Hi Rita
    what differences should we be looking for to distinguish ‘Striped’ and ‘Large Striped’ Greenhoods? I wasn’t absolutely sure of the species but came down on the side of P. alata because the flowers so closely matched a photo taken for me in another area of Box Ironbark and I couldn’t find P. robusta on DSE flora lists for either Sandon or Muckleford State Forests.

  3. Hi all,

    I have seen P. robusta flowering in Dean and Caroline’s place in Pound Lane Newstead at this time of year (photographed 18 July 2002).

    Kate, I would not go by DSE flora lists as my understanding is they are made by interpolating between relatively few remote survey plots (i.e. not ground verified for the level of detail you require). Do you know of the Castlemaine Field Naturalists “Castlemaine Plant List” ? You can buy one for about $5. This is what I use to see what species are known to be in an area (from actual observations by members of the club over a period of 30 years).

    Looking in “The Orchids of Bendigo” published by Bendigo Field Naturalists Club: P. robusta “resembles P. alata except for its stronger, more robust form”. The line drawing of P. alata in this publication shows it as a much taller plant than in Geoff’s photos and I wonder if we could be looking at another Greenhood orchid species altogther, one that is not in my Bendigo book? Dawn and I saw lots of colonies of short Greenhoods (that resemble the ones Geoff has photographed) in Cambelltown on the last community walk (26 June), but alas neither of us had a camera and we havent been back to get photos.

  4. Kate Sandiford

    Thanks Frances
    The greenhood colony that Geoff photographed had taller flowers last year, and looking at his photos, they seem to be getting shorter by the week. Interesting that there are so many colonies of these ‘short’ greenhoods about this winter. I was already wondering if the shortness might be seasonal and due to low temperature.

  5. I suspected this note might unleash a Pandora’s can of worms …. will be interested to see if we can arrive at a definitive answer!

  6. Geoff, I think you will find that the orchid is the Large Striped Greenhood, Pterostylus robusta, not Striped Greenhood, P. alata. I checked Backhouse and Jeanes The Orchids of Victoria, first published 1995, but I’m pretty sure the names are still the same. P. robusta is also known as the Sharp Leaf Greenhood and Green Shell Orchid. We (Castlemaine Field Nats) know of them from a spot on Captains Gully Road,
    Geoff, to answer your question on differences between the two. To quote from Backhouse and Jeanes,in part from the notes on P. robusta, “Distinguished readily from P. alata by its much larger flower on a generall shorter, thicker scape. ” it also is generally found north of the ranges in southern Mallee and Wimera, and around this area

  7. Also, it LOOKS like P. robusta! I have seen a few over the years, including a patch in Barkers Creek that unfortunatley now has a house where they used to be.

  8. Pingback: Pterostylis robusta! | Natural Newstead

  9. I have been following the debate. Checking on P. alata and robusta in Flora of Victoria the descriptions are very similar with the main difference bein flower size – P. alata 2cm and P. robusta 3-3.5cm. The Ballarat field nats saw a similar orchid at Fell’s Gully, Clunes in August 2010 which we called P. alata. I wish we had accurately measured the flower!

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