A short story of Cypripedium acaule (Pink Lady’s-slipper orchid) in an upstate South Carolina Heritage Preserve — 2013-05-08

Earlier this year, I decided that I’d track a particular Pink Lady’s-slipper orchid plant from spring sprouting to flowering. It’s well known among those who study native orchids, that they can put on some fantastically quick growth. Last year (2012), they were in full bloom by mid- to late April. However, this year, we had a late winter and a cool/wet spring.

So, I spent one day each week (about a week apart) from April 5 to May 8 in an area of upper Greenville County, South Carolina where I have seen and photographed these particular orchids for many years. This site is known as Eva Russell Chandler Heritage Preserve. It is a site that has been set aside by smart, forward-thinking people to protect and preserve archeological and botanical treasures that are scattered all over the state of South Carolina. These areas are managed by the South Carolina Department of Natural Resources (SCDNR). We currently have more than 70 such sites, many of which are located in the upstate of South Carolina.

Here is a closeup image of a Pink Lady’s-slipper orchid flower:

Pink Lady's-slipper orchid

The first trip I made to check on the orchid growth was on March 29, 2013. I knew where one particular plant had grown last year, because the stem supporting the old seed capsule was still standing. I carefully checked the ground around the base of the stem but found absolutely nothing — no sign of growth. Being determined to see this plant begin new growth, I returned one week later, on April 5, 2013. Here is what I found:

New growth of Pink Lady's-slipper orchid

That brown, stick-like object rising from the ground directly behind the plant bud is the stem of last year’s seed capsule.

I now had my “zero base” date for plant growth. Exactly one week later, April 12, 2013 I made the 45-minute trip back up to the Heritage Preserve to check on the growth of my study subject. Here is what I found:

more growth...

That’s a good amount of growth in just one week. It was my intention to return to the site in increments of exactly one week, but very heavy rain caused me to wait an additional day. So, on April 20, 2013, I made another visit to the site. Here is an image of the new growth:

more impressive growth

To me, that is some impressive growth for just eight days!

On April 26, 2013 (back on the weekly schedule), Here is how the plant looked:

Impressive growth, again...

Well, sometimes life gets in the way of good intentions, and I was not able to photograph that plant again until May 8, 2013 — a bit more than one month after it first poked through the ground. Here is the final result. Our subject plant is the one on the right:

Final result...

The following are some images of additional plants that were at or near the site of the subject plant:

The plant on the above left is a juvenile plant that will probably bloom in another year or so. When the plant first grows from seed, it has only a single leaf. If it survives past this stage, it probabaly has a good chance to bloom within three or four years. The plant on the above right is about one week or so from being in full bloom.

There is a bit of color showing on the flower on the above left image. It is probably only a few days from full bloom. The flowers on the pair of plants on the above right image have been fully developed for several days. Frequently, a single plant will initiate several plant sprouts (there can be as many as a dozen) from the same root growth. At this particular site, though, I have not seen more than two or three sprouts from a single root growth.

Following, are a few closeup shots of Pink Lady’s-slipper orchid flowers:

The flower in the above left image is shown next to last year’s seed capsule from the same plant. The flower in the above right image is positioned so that sunlight was shining through the lip, exposing and detailing the colored ridges on the reverse side of the lip.

Finally, I’ll show two images of flowers which have been selected by two, similar looking moths. These plants were about 1/2 mile (.8 km) apart. When I saw and photographed the flower and moth on the below left, I thought it was a bit unusual. I wondered why a moth would be attracted to the slit opening on the front of the lip. The Pink Lady’s-slipper orchid flower does not have a fragrance nor does it offer any nectar reward to its pollinators, so I’m still stumped as to why the moth chose this particular place to rest. When I saw the second flower and moth (below right), my suspicions were raised.

I’d like to hear an indentification of the moth species from blog readers so that I can properly label the image. In addition, if anyone has any thoughts about why this moth species would choose to light on the lip of this orchid, please don’t hesitate to share these thoughts with us.

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Update: Thanks to a well-read flickr buddy and a blog reader, I now have an identification:
Tetracis cachexiata or White Slant-line moth
Thanks guys, but I am still clueless why they are on the lip of the orchid…

Further update: Update! Here is a link to a blog that Charley Eiseman wrote about this orchid/moth phenomenon:

bugtracks.wordpress.com/2013/12/01/monthly-mystery-13-sla…
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This simple little study has proven to be very satisfying to me. Now, I will have a better idea of the bloom status for any particular plant after having seen this species in all of its stages from early sprouting to full bloom.

— Jim

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0 Responses

    1. Thanks, Charley! I’m very interested in hearing about any more information you come across about this phenomenon. I appreciate the link to your blog!

      — Jim

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