I wrote about early season orchids quite some time ago, and you can find that post here. This post will carry on with the orchid theme, but focus on species one might find in the later part of the season.
One of the orchids currently in flower at Rondeau is Small Green Wood Orchid (Platanthera clavellata).
An orchid that may still be in flower, but does not occur at Rondeau is White Fringed-Orchid (Platanthera blephariglottis). It has been recorded in wet prairie north of here, as well as in fens and bogs. I photographed this orchid in a beautiful bog in Huron County a few years ago.
An attempt was made to grow some plants from seed in the mid-1990s and plant the young plants in promising habitat in the Ojibway Prairie area, where other historical records indicated they once occurred. Follow-up searches to date have not indicated that the plantings were successful, but it takes a few years for plants to mature and flower and it has been ten years or more since anyone last investigated.
One of the rarest orchids in Canada is one that will be flowering as soon as early August: Nodding Pogonia (Triphora trianthophora). It does occur at Rondeau, and is currently the only known location for it in the entire country.
Towards the middle of August, one of the several species of Ladies'-tresses orchids will appear. A rare one, which does not occur at Rondeau but on rare prairies elsewhere, is the Southern Slender Ladies'-tresses (Spiranthes lacera var gracilis). Note the spiralling arrangement of flowers, each of which as a distinctive green centre.
Another Spiranthes is the Yellow Ladies'-tresses (Spiranthes ochroleuca). One of the sites in Chatham-Kent seems to have been destroyed, but another small population on private property is still around. I photographed this in September of 2014, although it is a little past its best. It has a creamy yellow centre of its flower.
The smallest Spiranthes that grows in Ontario, but has yet to be found at Rondeau, is Oval Ladies'-tresses (Spiranthes ovalis). One can tell from this next photo, where it is on the left and S. magnicamporum is on the right, just how small it is.
So there is a bit of information on some of the orchids present in southern Ontario in the latter part of the season!