Francis Marion National Forest, Part 1 — orchids, carnivorous plants, and other amazing stuff — 2014-05-03
Early on Saturday morning (5:30 am to be precise), May 3, I left for one of my favorite places for Spring wildflowers — the Francis Marion National Forest in Berkeley County, near Charleston, South Carolina. It’s a large holding – more than 250,000 acres of bottom-land swamps and Longleaf pine savannahs. Today, it is the Longleaf pine savannahs that interest me, since they provide great habitat for an early blooming wildflower, Calopogon barbatus or Bearded Grass-pink orchid.
I was joined by two buddies from Atlanta, Georgia, Alan Cressler and Steve Bowling. Alan has met me in the FMNF on several occasions to look for carnivorous plants and orchid species. Alan especially wanted to see a fairly rare pitcher plant hybrid that grows in abundance in the FMNF. However, since that part of the trip has so many pictures and descriptions associated with it, that section will be highlighted in Part 2 of this blog entry (coming very soon).
First, though, I would like to cover the other sights that we saw in the FMNF. I’m always on the lookout for wild native orchids, my favorite wildflower. Early May is the time of year that we can expect to find Calopogon barbatus or Bearded Grass-pink orchid in the Longleaf pine savannahs of the Atlantic Coastal Plain. It is a diminutive species growing not more than 6-10 inches (15-25 cm) tall. It can have as many as 8 1-inch (2.5 cm) flowers on a single stem, but it usually has 3-5 flowers. At any one time, there will be at most 4 flowers in bloom, the others either in bud or withered and past bloom. Here is an image of a typical Calopogon barbatus just beginning to bloom:
Like the four other North American Calopogon species, it has a single, narrow leaf, but at anthesis, it is very small and usually pressed against the flower stem. It will continue to grow larger as the plant blooms and the seed capsules ripen.
We found a number of plants scattered in the wet Longleaf pine savannahs along Steed Creek Road, the main road that cuts directly through the center of the forest. Here are some images of those flowering plants:
Botanical talk follows: This particular orchid genus (Calopogon) has what’s known as non-resupinate flowers. This means that the labellum or lip of the flower is uppermost. With most of the other orchid genera, the flower bud presents the lip as uppermost, but as the flower develops, the flower stem twists to show the lip as being lowermost when the flower is fully open – thus it is resupinate or upside down and facing upward.
This genus has a rather unique pollination scheme. It is pollinated by bumble bees. A bumble bee is quite large in proportion to the 1-inch (2.5 cm) flower which helps greatly in the pollination process. The golden-yellow fuzzy structure at the top of the lip looks like pollen but it is not pollen. It is actually a set of knobby protrusions called pseudo-pollen. This attracts bumble bees whose number one job in life is the gathering of pollen to feed their young. When the bee lands on this pseudo-pollen, its weight causes the lip to fold forward and downward. This is facilitated by a hinge on the lower portion of the lip. As the bee and the lip curve downward, the back of the bee is precisely positioned over the true pollen, which is at the end of the curved portion of the column. The first time this happens, pollen is transferred to the back of the bee. The next time this happens (on another flower), this pollen is transferred to the stigma where it completes the pollination process. Apparently, this happens only with naive, newly hatched bees. Since there is no pollen reward for the bee, it will soon lose interest in this type of flower and find a species that will give it an actual reward.
As I was photographing the orchids, Alan’s keen eye was focusing on a nearby tree. It happens that a large lizard was sunning on the tree. This turns out to be one of our largest lizards: Eumeces (formerly Plestiodon) fasciatus or Five-lined Skink. Here is the male in its vivid breeding colors:
It was amazingly calm and remained on the side of the longleaf pine for a long period of time, putting up with cameras flashing and close inspection by three gawking botanists. A nice break from wildflowers…
Nearby, there was a carnivorous plant that I had hoped to find on this trip. It is Pinguicula lutea or Yellow Butterwort. This is a member of the group of carnivorous plants that is considered a Passive type. The two types are Active and Passive. The Active types have a mechanism built into the plant that makes movement in order to capture its prey. Dionaea muscipula or Venus’ fly-trap is an example of an Active type of carnivorous plant with its spring-loaded traps. The plants in the genus Pinguicula capture their prey by the use of sticky glands on the top side of the leaves – no active movement by the plant is required. Once an insect crawls up onto the rosette of ground-level leaves, it is caught in the sticky substance coating the leaf’s surface. There are additional glands scattered across the leaf which aid in the digestion of the insects.
This particular species, Pinguicula lutea, has a bright yellow flower. This makes it very easy to spot between the leaves of the grasses and the pine needles on the forest floor:
Off in the distance, we could see some 3-foot (1 meter) spikes of tiny, bright white flowers waving back and forth in the breeze. These turned out to be Stenanthium densum (formerly Zigadenus densus) or Fly Poison also known as Osceola’s Plume:
This plant got one of its common names, Fly Poison, from the mixture of the crushed bulb and a bit of sugar used to attract and kill flies. All parts of the plant are toxic, but the bulb is especially toxic.
After finishing up at this location, Alan suggested that we visit the site of a relatively rare Sarracenia or Pitcher Plant hybrid. This particular hybrid is rare because the two parent species generally bloom about a week to ten days apart. They do share the same pollinator, a Bombus or Bumble Bee species, but if both plants are not in flower at the same time, there will be no pollination across the two species. The two species are Sarracenia flava or Yellow Pitcher Plant and Sarracenia minor or Hooded Pitcher Plant. Both of these species are plentiful in the FMNF, but at this site, Sarracenia flava usually blooms well before Sarracenia minor. Fortunately, a perfect set of circumstances had caused the two species to bloom simultaneously and near enough to each other to allow cross-pollination that produced the hybrid. It is known as Sarracenia Xharperi or Harper’s hybrid Pitcher Plant.
We knew where there was one large clump of this hybrid in a fairly remote portion of the FMNF, so we set off to try to relocate it. We hiked to the spot, but after week of heavy rain, the plants were surrounded by 6 inches (15 cm) of standing water. We were prepared with our rubber boots, so this did not pose a big problem. Here is a panoramic shot of the large clump of this hybrid Pitcher Plant:
Here are some additional shots that give a better view of the pitchers and flowers:
One other fine plant we saw was Lupinus villosus Lady Lupine. I had not seen it down there in a few years, so it was nice to be able to photograph it, again. This species does not have the typical, sunburst-leaf shape of most Lupinus species, but rather it has coarsely hairy, erect, lance-shaped leaves. Lady Lupine is a short-lived perennial, and most plants do not flower their first year. They flower sparingly the second, and then reach their full potential in the third when they bloom profusely. The flower spikes are around 1 foot (30 cm) tall:
Seems like everywhere I go in the southeast there are violets. On this trip, we saw several species of violets. One, in particular, got our attention because of the size of its flowers – almost 1 inch (2.5 cm) across! They were gorgeous. The species is Viola septemloba or Southern Coastal Violet. It’s not particularly rare, but it’s not seen frequently at this location due to the dense layer of vegetation in some of the savannahs. Recent burns in the FMNF gave these a good start by reducing the vegetative competition:
Well, it was time for me to leave our get-together and head northeast toward the Green Swamp Preserve and a new location for me, Shaken Creek Preserve. On Sunday morning, I would be meeting up with my North Carolina buddies, Skip Pudney and Kelvin Taylor. Stay tuned to this spot for the details, but next will be Part 2 of this trip to the Francis Marion National Forest where we found a huge variety of the amazingly colorful flowers of the hybrid Pitcher Plant, Sarracenia Xrehderi…