Thirty-first Orchid of the Season

It is amazing that by August 1st the native orchid season was already over this year.  Usually the season extends well into August and there are orchids to be found even into September, but not this year - it was too hot and too dry.  August 1st was the last field trip for the Washington Native Orchid Society and a small group of us visited several sites in eastern Washington near the Columbia River to see the endangered Ute Ladies'-tresses, Spiranthes diluvialis.  Like so many other species they were very few in number this year and were totally absent at one site.  We did find enough for photographs, however, though even those plants  were past their prime.  Spiranthes diluvialis is a natural hybrid of Spiranthes magnicamporum, the Great Plains Ladies'-tresses, which does not even grow in Washington, and Spiranthes romanzoffiana, the Hooded Ladies'-tresses.  It is taller than the Hooded Ladies'-tresses, up to 60 cm, though many of the plants we saw were much shorter.  The 1 cm flowers have a fringed appearance that immediately distinguishes them from our other two Spiranthes.

Twelfth Orchid of the Season

We made a brief stop recently in north-central Washington to see a patch of the Columbia Hybrid Lady's Slippers, Cypripedium x columbianum, a natural hybrid of the Mountain Lady's Slipper, Cypripedium montanum and the Yellow Lady's Slipper, Cypripedium parviflorum var. pubescens.  In this hybrid population, which grows mixed together, there are flowers that look like both parents, with either a yellow or white lip, as well as flowers that are clearly intermediate between the parents, the lips a soft yellow or off-white color.  When we visited this patch, it was obvious that it had not been a very good year with fewer than normal plants and we also found most of them finished, though we did take enough photos for a blog post.

Cypripedium x columbianum

Spiranthes diluvialis

Spiranthes diluvialis, the Ute Ladies'-tresses, was the last of the native orchids we saw this season and we saw it for the first time ever in the Columbia River basin.  It is a natural hybrid of Spiranthes romanzoffiana, the Hooded Ladies'-tresses, and Spiranthes magnicamporum, the Great Plans Ladies'-tresses, a species that does not grow in the Pacific Northwest.  It is very rare and listed as Federally threatened, due especially to habitat destruction.  We had looked for it previous years but with better information we found it this season and found it growing in the kind of location it prefers, along a river and in an area that is often inundated well into the summer months.  It is a beautiful species with white to near-white flowers, plants that are 30 cm tall, and flowers that are tubular and 1.5 cm long.  The flowers like most of the Spiranthes are "braided" around the stem, adding to the beauty of the species.

Platanthera natual hybrid (?)

While looking for and photographing different Platanthera/Piperia species, I found this oddity which appears to be a natural hybrid between Platanthera transversa, the Flat-spurred Piperia, and Platanthera elegans, the Elegant Piperia, or instead of the latter species, Platanthera elongata, the Long-spurred Piperia.  If it is not a natural hybrid the only other possibility is that it is an odd, short-spurred form of Platanthera transversa.  All three of these species grow in the location I was visiting, though Platanthera elegans only on the other side of the hill where this was found.  The flowers are colored like the flowers of Platanthera transversa, but the spur is not the long, horizontal spur of that species.  The spur looks like that of Platanthera elegans or Platanthera elongata, both of which curve downward, but it is much shorter than the spur of Platanthera elongata.  The plant was growing with other plants of Platanthera transversa.  I've included photos of the three species found in the area for comparison.

July 25

(Whidbey Island)

Piperia transversa

Piperia elegans

Piperia elongata