Friday, September 20, 2013

The End of Another Season (2013)

The 2013 native orchid season was very unusual in some ways.  It began very early with a warm wet spring and ended very early with a warm dry summer.  It was good orchid-hunting season for us in our own state, however, with one variety, two species and one natural hybrid seen in Washington for the first time, along with several new locations found for the all-white form of the Western Fairy Slipper and with our first look at the unspotted form of the Western Spotted Coralroot.

On a trip to Canada we saw two new species that we had not seen before, as well as a new variety of the Small Round-leaf Orchis, a very common northern species that is not found in Washington.  All of these are very rare and elusive and we are very thankful to a friend, Ben Rostron, for trusting us enough to take us to see them in their closely guarded locations.  This trip was the high point of the orchid season for us and we hope to make the trip again next year.

The two species that we had not seen before in Washington were Cypripedium parviflorum and the elusive and tiny Platanthera chorisiana.  The former is very rare in Washington and the latter rare throughout its range.  We also saw the natural hybrid of Cypripedium parviflorum and Cypripedium montanum, Cypripedium x columbianum.  Though we had seen this hybrid before we were delighted to find it growing in a mixed population that included both parents.

We also saw for the first time in Washington, the Eastern Fairy Slipper, Calypso bulbosa var. americana.  We had seen this species in British Columbia but not in our state.  In the location where we found it we looked for the natural hybrid of the two varieties of Fairy Slippers, Calypso bulbosa x kostiukiae, but could not find it, another task for next season.  The Eastern Fairy Slipper is notable for its yellow beard and unspotted central lip lobe.

The new species seen in Canada were Liparis loeslii, the Fen Orchis and Malaxis brachypoda, the White Adder's Mouth.  Both of these are rather insignificant and would probably pass unnoticed to the casual observer, but we were delighted to see them for their rarity.  We also saw on this trip Amerorchis rotundifolia fma. lineata, the striped-lip form of the common Small Round-leaf Orchis.  This form is in our opinion even more beautiful than the ordinary form.

We had seen the white form of the Western Fairy Slipper, Calypso bulbosa fma. nivea, once before, but we discovered this spring that that plant had been dug up and stolen.  We found several more locations for it, however, and are keeping the location a closely-guarded secret.  We also found a near-white form with only hints of color, what would probably be called a semi-alba form in the orchid world.  That location, too, we are keeping secret or sharing only with those we trust.

Finally, we were taken by another friend to see the yellow, unspotted form of the Western Spotted Coralroot, Corallorhiza maculata var. occidentalis fma. immaculata, a spectacular plant whose location will also remain undisclosed.  These, with new locations for many other species, with visits to many locations that we had visited before, and with all the other natural beauties we see on these excursions, made for a very profitable and interesting season.

One note: we found through a friend that one species reported from the Pacific Northwest, Wister's Coralroot, Corallorhiza wisteriana is not actually found there.  The original location, so we were informed, was in a garden where it had been transplanted from further east.  That leaves only two species from Washington that we have not seen, Listera convallarioides, the Broad-lipped Twayblade, and Spiranthes diluvialis, the Ute Ladies-tresses.

Monday, September 16, 2013

The Northwest's Green-flowered Platantheras

The green-flowered Platantheras with the exception of the tiny and rare Platanthera chorisiana (Chamiso's Orchid) are very difficult to tell apart and most experts consider them to be a series of species many of which hybridize with one another and thus intergrade.  This is our experience as well.  We have found plants that very closely fit the description of each species, but have also found endless numbers of plants that are very difficult to identify and seem to have characteristics of more than one species.

The species are Platanthera aquilonis, huronensis, sparsiflora and stricta and a number of hybrids, Platanthera x correllii, x estesii and x lassenii, the first a hybrid of Platanthera aquilonis and stricta and the both the latter hybrids of the white-flowered Platanthera dilatata (with P. stricta and P. sparsiflora).  The white-flowered Platanthera dilatata with its three varieties cannot be confused with any of the green-flowered species, but because it hybridizes with them must be considered here also.

Of these species, Platanthera sparsiflora, the Few-Flowered Rein Orchis, is the easiest to identify and the most clearly defined as a species in our experience, though our experience of this species is somewhat limited since it is at the extreme northern limit of its range in Washington.  The narrow flowers, usually widely spaced on tall spikes are the identifying features.  It is found in Oregon, California, Nevada, Utah, Colorado, Arizona and New Mexico and in southern Oregon and northern California often grows in serpentine soils.

This species has a named hybrid with Platanthera dilatata, Platanthera x lassenii, Lassen's Hybrid Rein Orchis, but this is known only from cultivation, at least to my knowledge.  I know of no one who has seen it in the wild or seen anything that might resemble it.  The pictures of it I have seen show a spidery pale green flower that looks a bit like the Platanthera dilatata parent.  There are also several varieties and new species that have been separated from this species, but they are not found in the northwest.

Next is Platanthera aquilonis, the Northern Green Bog Orchis, distinguished by its green flowers with a yellowish lip, a lip that is more or less straight-sided, a club-shaped spur that is curved forward and shorter than the lip, an absence of scent and anther sacs that are low in the flower, widely separated at the base and close together at the top.  The pictures below represent close approximations to the description of this species, but as we shall see there are plants that only partly fit this description and have also characteristics of other species.

Platanthera huronensis, the Green Bog Orchis, can be difficult to distinguish from the previous species.  Though it is ordinarily a whitish-green, the color varies and the two species cannot be distinguished by color alone.  Along with the color, its features are a lip that is not yellowish, a lip that has a dilated or narrowed base, a spur that is not as distinctly thickened as the previous species and that is equal in length to the lip and does not curve forward, with anther sacs toward the top of the flower and almost parallel.

Very similar to this species is the natural hybrid of Platanthera dilatata and stricta, P. x estesii.  In our experience the slender curved spur, and the widened base of the lip, both very much like the spur and lip of the Platanthera dilatata parent are distinctive as well as the whitish color.  This hybrid seems quite common - we have seen it in the Olympics, in Yellowstone National Park and in the Canadian Rockies - and if we have correctly identified it would indicate that the two parents rather freely hybridize with one another.  In all these locations the two parents grow and flower together.

Platanthera stricta, the Slender Bog Orchis, is distinguished by rather small green flowers, a straight-sided lip and a spur described as "scrotiform," i.e. with an inflated tip, a spur that is shorter than the length of the flower.  This species is very common and blooms along-side of and concurrently with the other green-flowered Platantheras.  At first meeting it seems rather easy to identify until one begins to find plants that do not match the description of the species exactly and have characteristics of the other species.

Finally, here are a couple of pictures of flowers that do not clearly fit any of the descriptions.  The first has every characteristic of Platanthera stricta, spur shape and lip shape especially, but has a lip that is very yellow, a characteristic of Platanthera aquilonis and the reason I identified it in the field as the latter species.  The second has all the characteristics of Platanthera stricta, too, except the spur in length and shape is much more like that of Platanthera huronensis.  This would probably be classified as Platanthera stricta but is not completely characteristic of that species.

Wednesday, September 11, 2013

Varieties and Forms of Calypso bulbosa

The Fairy Slipper, Calypso bulbosa, has two American varieties, The Western Fairy Slipper, variety occidentalis, and the Eastern Fairy Slipper, variety americana.  There are two other varieties also, variety bulbosa, found in Europe and Asia, and variety speciosa, found in Japan, but neither of these is found in North America and are not the subject of this post.

The two native varieties' Latin names reflect their distribution, but the English names do not.  The Western Fairy Slipper is found only in the far west and is well named "occidentalis."  The Eastern Fairy Slipper is found all across northern North America except for a small area in the far west along the Pacific Coast and is better named "americana" than "Eastern."

The Eastern Fairy Slipper is easily distinguished by the yellow beard in the center of the lip and by the lack of brown spotting on the central lobe of the lip.  It has several forms, a white-flowered form, forma albiflora (not shown here - we've not seen it), a pink-flowered form also shown below, forma rosea, and a two-flowered form, forma biflora.

Calypso bulbosa var. americana

 Calypso bulbosa var. americana fma. rosea

The Western Fairy Slipper tends to be somewhat taller and is not as vividly colored as the other variety.  It has a white beard and heavy brownish-purple spotting.  This spotting varies in intensity and color, as does the pink color of the rest of the flower, which can be a very deep lavender-pink or a pink so pale it is nearly white.  It has only one form, a pure white form, forma nivea.

Calypso bulbosa var. occidentalis

Calypso bulbosa var. occidentalis fma. nivea

There is also a very rare hybrid between the two species, Calypso bulbosa x kostiukiae.  It is named after its discoverer and has the yellow beard of the eastern Fairy Slipper and a finely spotted lip that comes from the Western Fairy Slipper.  We finally found this hybrid in a location where it had been reported and where we had looked several years in a ro.

Calypso bulbosa x kostiukiae

Besides these varieties and forms there is considerable color variation in the flowers, especially of the Western Fairy Slipper.  They vary from the very intensely colored flowers to near-albinos as shown below.  The near-albino is clearly that for the lack of spotting on the lip and the nearly yellow color at the back of the pouch, where the flower is normally a brownish-purple.