Monday, 10 October 2016

Half time for Carwoola orchids.

At various times over the last three years I have posted about my monitoring of colonies of 2 species of orchid: Cyanicula caerulea and Glossodia major.  When the Cyanicula commenced flowering this year I included some images of them so it is only fair that I start this post with some images of the Glossodia.

This first one givesan idea of the habitat in which they are growing.
 It is of interest that this year the colony appears to have spread more out into the grassy area rather than the main clump of Kunzea where they have been in the past.

Here is a shot of one flower.
 Zooming in a bit further this close-up of the labellum and column clearly shows the (white) wax lip.
Of course I would never call them waxlips, even though the vernacular names of plants appear to be far more stable (in a given region) than the binomials.

The next image is pretty naff but does show the only insect I have seen paying attention to these plants so far.
One of the benefits of studying these two species is that the Glossodia gets into gear just as the Cyanicula are beginning to calm down.  This first chart shows the overlap for 2016 (up to 10 October.)
A first point to note is that for both species the total number of flowers in the colonies is the highest by far of the three years I have been counting them.  When the Glossodia has finished I will do some head-scratching about the likely reason(s) for this.

The Cyanicula are actually in three sites, but for this post I am aggregating them.  The second chart shows the total number of this species recorded by date over the three years.  (Breaks in the series are periods when we were elsewhere: the smoothing effect of the polynomial overcomes that, at least for illustrative purposes.)
This clearly shows that there were both many more flowers in total in 2016 and that the flowering season was much longer.  With respect to the second point I took particular note of when some flowers first emerged and they have lasted >3 weeks so far (and in some cases are still in good shape).  That is a lot longer than I had expected

The Glossodia are only studies in a single site.  I'll note in passing that in 2016 they are coming up in many places I haven't seen them in the past  Here is a 3-year chart similar to that for the Cyanicula.

This clearly shows that 2016 is the most productive of the three years.  The number of flowers is well above the maximum for 2014 and there are many buds yet to open.  This is despite a relatively slow start to the season.  Purely for amusement I applied a 10-day forward projection to the polynomial function calculated by Excel which suggested the number of flowers will peak at about 380 on about the 15th of October, followed by a very rapid decline.  We shall see!

After a couple more days I updated the graph on the 12th with the projection turned on.  Note that I may have double counted a few on the 10th and I suspect that cold weather on the 11th meant that a few flowers were not open and thus not counted.  (The main purpose of the trend line is to smooth out such silliness, not as a base for projections.)
The big change is that the projection sees 12 October as the peak, with a drop to zero in the next week.  As I noticed quite a few unopened buds on the 12th I see this as unlikely. (In fact on the 13th the count - with Frances engaged to check I didn't do any serious under or over-counting - was 308.

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