Late summer orchids of Rondeau, all are species at risk!

 There are several highlights for botanizing later in the summer. Certainly the main highlight for me is to check on three orchid species that are found at Rondeau, all of which are quite rare in Ontario. One is so rare that its only Canadian location is at Rondeau. Another one is quite restricted, but so very small that the average person would not even see it. The third, and latest flowering one, is rare, but relatively widespread in the park and generally more visible.

 Keen botanists will likely already know the three I am talking about. The first, and rarest one, is the Nodding Pogonia (Triphora trianthophoros). 

Its peak time of flowering is typically the third week of August, although on rare occasions I have seen one or more in flower on even the last day of July. This year I went out into one of its best known locations on August 1, just to see what was happening, and was quite surprised to see several in flower. One even had a double flower!

The tricky thing with this orchid is its flowering strategy. All the buds develop to a certain stage, and then remain as is. It takes a fairly significant drop in the overnight temperature to trigger the buds to open on the morning of the second day following this temperature drop. All the buds that are ready will open, but just for a single day, and it may be a week before the next suitable temperature drop triggers the next set of buds to open.

The weather this August was anything but suitable for this flowering strategy. An overnight temperature would seem suitable, but then the next three nights would see the temperature drop even more! I think the plants were a little confused with this abnormal sequence, and as a result, their flowering was difficult to predict. On more than one occasion I went out expecting, or at least hoping, to see some in flower, but in some cases they flowered the day before and were not worth bothering to photograph. And the next set of buds were not well developed at all. This next photo shows what a single plant looks like, from a distance of about 6", with a 100m macro lens! They can be easily missed, even when one knows exactly what to look for, so I seldom go out unless I am quite sure they will be in flower, and if it is the wrong day, I don't spend much time looking so as to not accidentally step on them.

I do know where some are likely to be found, even if not flowering, and by being extra careful, I managed to find some that were tucked beside a fallen log, and almost impossible to see. This next photo is of a pair of even tinier plants with very undeveloped flower buds, and again, photographed with a 100mm macro lens from a close distance. The plants are merely 4-5 cm high. Even at that, I greatly cropped the photo to get this.

Overall it was one of the poorest years I can remember in my 50+ years of monitoring this endangered orchid. Probably the relatively dry weather at a critical time was partly the cause. However I did manage to get a few photos. These next two were taken in the 3rd week of August window. All were almost pure white, and while I always hope for some with a magenta tinge that I find even more attractive, the second photo is the only one that had even a very slight magenta tinge. Ones with a magenta tinge usually occur towards the end of the flowering season. Oh well, maybe next year.

 After blooming, the seed pods develop, as this next photo shows. Upon ripening, the seed pods will become erect, and start to dry, with the sides of the pod starting to split open so that a slight gust of wind will cause the seeds inside to disperse.

The second orchid I referred to, is about the same size as the previous one, and at least once the flowers open up, will remain open for several days. However for the more common variety of this one, Autumn Coralroot (Corallorhiza odontorhiza) which is also rare, the flowers don't open, but are self-pollinated! The rarer variety, known as Pringle's Coralroot and shown here, has flowers that do open. This first photo shows a group of four plants.

A closer look at the arrangement of flowers.

Closer....

And finally, a 'head-on' view of the lip of a single flower, which is probably only about 4 mm wide.

Not exactly a show piece for the horticultural industry, but an interesting orchid nonetheless, and it is native!

The third, and last orchid to be found flowering at Rondeau is the more common of these three. It is known as Great Plain's Ladies' Tresses (Spiranthes magnicamporum).

I found my first one with a few of the lower flowers starting to open up on September 13.

A couple of days later, there were a few more starting to open.

It is rare that all of the flowers are open at the same time, but sometimes most are. There are other species in the Spiranthes genus that look similar. A couple of the key characteristics of this one is that when in flower, it has a 'fragrance' that I think is similar to hot plastic. But without getting close enough to smell it, a close look shows a slightly yellow/tan colour well inside an open flower. None of the other Spiranthes have this coloration.

There is some slight hairiness to the outer white parts of the flower, and the sepals flare slightly back if viewed from the side.

 That's about it for Rondeau's orchids for this year. But by next May, another one of the 19 species of orchids will appear. Can't wait!

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Late summer orchids

 This post has been in the works for a few weeks, since there have been a few orchid species typical of the late summer, and several are rather rare. Currently there are 19 species of orchids known from Rondeau, 18 if which are native. I have seen all but one species, so far. Of course one of the highlight orchids is that endangered species, Nodding Pogonia a.k.a. Three-Bird's Orchid, which is currently only known in Canada at Rondeau.

It used to be known from a private woodlot in eastern Essex County, but hasn't been seen there for several decades. Forest changes and activities in the forest have undoubtedly resulted in its demise there, but it is still possible. Access to privately owned properties have become increasingly challenging, since the presence of an endangered species might result in restrictions to what the landowner has planned for their property.

Regardless, this species has been known from Rondeau since about the mid 1960s, and their are several locations in the park. Fortunately for the species, these locations are mostly away from existing trails and roadways, although on rare occasion one or more can pop up within view of a trail. I have been following/surveying this orchid since 1973, when I encountered it during my first year of working on the naturalist staff of Rondeau.

It may begin flowering in very late July and even flower into the middle of September, but its peak flowering time is about the third week in August. What makes this orchid so intriguing is that it is very small, and flowering is very weather dependent. All of the potential buds develop to a certain stage, and then stop. It is only after a significant drop in the overnight temperature, that all of those buds at this stage will open. And then they will only remain open for a day, and it may be a week or so before the next set of buds will open, depending on the temperature triggers.

This is what a developing orchid looks like before flowering. You can see by its size relative to last year's fallen leaves it is emerging through, it is anything but showy.

 Its scientific name, Triphora trianthophoros, as well as the Three-Bird's Orchid name, is based on the fact that usually a plant will produce three buds, and on rare occasions, all three will open on the same day! This next photo shows a single plant, with all three flowers open at once. I don't see this every year, but this photo was taken in 2024.

 

 This photo of the three flowers is located in the extreme upper left of this next photo.

I was quite pleased to come across this concentration of the orchid. Normally they will occur in small groups of three or four, or sometimes just be singles scattered on the forest floor. This was one of the largest concentrations I have seen in recent years. They are so photogenic, I have many dozens of photos from over the years. Certainly a macro lens and flash is required for the best photos.

Sometimes one gets a bit of a surprise along with the photo. This next photo is an example. At first I thought it was just another, typical flower.....

...but when I got a closer look at it on the computer, I noticed something peeking out.

I am not sure exactly what it is, but it is possibly a pollinator. When I was studying this orchid in the 1980s in preparation for writing the official status report, I collected some pollinator insects found on the plants, and it turned out they were mostly of the Halictid group which are types of sweat bees. This individual isn't fully shown, so it is not conclusive, but it has a strong resemblance to members of that group of insects.

A full frontal look at a plant with a single flower, may show the single, small roundish leaf, as in the following photo.

I particularly like the ones that have a tinge of magenta in the flower. Some are almost pure white, but it seems that later flowering ones are more likely to have the magenta tinge. I don't know what causes this, and some years they are almost all white ones.

Moving on to other late summer orchids, I have seen this next one called the Sphinx Ladies'-tresses.

Fairly similar, but flowering a bit later, usually about the middle of September, is this next one, which is called Great Plains Ladies'-tresses. It is a bit larger than the Sphinx and has a slightly yellowish tinge to it, especially when you look down the 'throat' of the flower. It also has a more fragrant scent to it.

The last orchid to flower at Rondeau is this next one, the Autumn Coralroot. And yes, this photo shows it in flower! There are two varieties of this orchid, and one will look like this, with a very small flower that hardly opens and droops downward, but the seed capsule forms anyway. This orchid is fairly rare throughout its range, and although I didn't look intensively for it this year, I only came across this single plant. However being as small as it is, and it isn't exactly showy, it likely occurs in places scattered throughout the pine-oak forest of Rondeau.

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Birds, orchids and a bit of catching up

 Birds continue to be one of my things of focus when I am out of doors, of course. An outing yesterday to Rondeau resulted in seeing a good variety, especially of warblers and other small passeriformes, but they were hard to get photos of as they darted in and out of berry bushes that lined the trails and roads. I also scanned the lake, hoping that my first of season Red-throated Loon might be in sight, but it was not to be. I did see about a dozen Common Loons, however, and relatively close.

There likely were more, as they spent a lot of time diving under, and so it was hard to tell exact numbers. I'm sure a scope and more time would have revealed quite a few more. They will be increasing in numbers as they move southwards from their northern lakes.

The only warbler that I got on camera was one of the dozens and dozens of Yellow-rumped Warblers, which greatly outnumbered all other species.

I did take a bit of time to photograph a few tree species that I hadn't bothered much with in the past. Some are native such as Green Ash

Many fruit

This species shows moderately long leaf petioles, not as long as those on White Ash, but certainly a lot longer as those on Black Ash.

Eastern Cottonwood

Swamp White Oak, from a few years ago

....and White Ash, which has much longer leaf petioles. All native ash species are considered to be at risk, since the Emerald Ash Borer (EAB) that arrived a couple of decades ago has killed off many. Fortunately even relatively young individuals produce seeds, so that there is a lot of regeneration going on, and maybe eventually the species will once again dominate native forests. They may not reach the longevity and large sizes of before the EAB days. Time will tell.

under side

upper side

And some that I photographed are not native, but fairly abundant, such as Black Locust. The first photo shows the typical leaf arrangement, with the leaves showing signs of a mining insect.

This next photo shows the typical double thorn at the base of some of the leaves on a main stem.

Northern Catalpa, shown next, is also a non-native species. It had been planted by various cottagers many years ago, and some of the fruits, and therefore new individuals, are showing up in places between Lakeshore Road and Harrison Trail.

Another non-native species, and the origin in the park is unclear, is White Popular, which can grow in large clones, especially in the sandy openings along the lake shore. The leaves are distinctive with their white edges, and quite whitish undersides.

On one occasion I took a quick look at a fallen branch along the trail, and noted this nest. It is likely a vireo nest, and given the location in the main part of the beech-maple forest, is a Red-eyed Vireo nest. This vireo species is by far the most abundant of the vireos at Rondeau,

I also saw this Northern Watersnake out for a stroll along Harrison Trail. It is quite a ways from what I would consider its normal habitat, but there it was.

One of the things I hadn't really discussed much in blog posts of a few weeks ago, is the current status of one of Canada's rarest orchids, the Nodding Pogonia. It wasn't a great year for them, although I did see several dozen in the general vicinity of the main patch. It was quite a few less than the sometimes several hundred I see here.

Most were singles, and were predominantly white. I always look forward to seeing the more magenta colour forms, but it didn't happen this year. And I missed the actual single flowering day on a few occasions, so sometimes I just saw them the day past their flowering, and the photo below shows what they look like then. We are looking at trying to be more accurate in knowing which day they will flower as it is very much a factor of overnight temperature, but that is a topic for another post.

Most were single blooms, but I did see a couple of double blooms. No triple blooms that I saw this year.

Another orchid that isn't nearly as rare, but still not a common species, is this next one, the Great Plain's Ladies' Tresses, which was at its peak in late September. The individual flowers don't last long, as you can see from this next photo, as the lowest flowers are already finishing up while the uppermost ones haven't begun to open. The unusual warmth at the time likely had some role to play.

And finally, just an update regarding my book 'Life on a Sandspit'.

I have expanded the locations where it is available. People have already been purchasing some for Christmas gifts! 

The locations now include the following:

Bayview Market, Rondeau

Book Brothers, Chatham

Mindful, Blenheim

Mitton's Jeweller's and gifts, Ridgetown

Five-Eau, Erieau

Molly and OJ's, Erieau

Sydenham Field Naturalists, Wallaceburg

Friend's of Rondeau, Rondeau Visitor Centre (although very reduced hours, and that gift shop may be closed until the Christmas break)

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