BY TAL GALTON
A summer orchid hunt in the woods of Western North Carolina is an exercise in discernment. Many of these precious mountain wildflowers are a shade of rusty maroon, perfectly blending into the backdrop of leaf litter. Others grow in the shadows of rhododendron. Even orchids that aren’t rare and aren’t camouflaged can be hard to find. For instance, you need keen eyes and perfect timing to spot the elusive three birds orchid (Triphora trianthophora). To find this flower, wait until the first spell of cool nights in August. Seek out an undisturbed rhododendron thicket, and with attentive study of the forest floor, you may spot this tiny pink and white jewel of a flower rising 8 inches off the ground on a nearly featureless stalk. Each flower is only open for a day, so become a rhodie-roaming regular if you want to catch a glimpse of this rare spectacle.
Orchid flowers are renowned for their fragile beauty. Tropical orchids are popular houseplants and are widely known for their exotic flowers. Most folks don’t realize that native orchids are a common but elusive feature of our temperate mountain forests. The orchid family is among the most diverse families of flowering plants, with nearly 30,000 species. While most of these species live in the tropics, at least 50 species are found in the Southern Appalachians. For an in-depth look, check out the best field guide on our local orchids, Native Orchids of the Southern Appalachian Mountains by Stanley Bentley. Native orchids are remarkable little plants, and you don’t need to be an expert botanist to learn the common ones; in my little corner of WNC, I have observed at least half of the varieties featured in the book.
On an orchid walk, the first thing I tell people is that orchids are extremely tight with the local fungi population. In ecology, this is known as a mycorrhizal relationship (“myco” means fungus, and “rhiz” means root; it’s pronounced “mike-o-rise-al”). Most tropical orchids are epiphytes. They live on tree branches and have no direct contact with the forest floor, so they don’t get nutrition from soil; recent research shows that epiphytic orchids are assisted by fungi. Our local (temperate) orchids are not epiphytes, but they often live in plant communities that have notoriously poor and acidic soil. Some varieties ―coralroot orchids, for example ― don’t even have chlorophyll for photosynthesis because they get all of their energy from their fungal partners.
Even orchids with green leaves depend on fungi for a range of plant functions, starting with germination. One feature common to orchids is their tiny seed size. Orchid seeds are dustlike specks that are simple plant embryos ― they lack the endosperm that serves as baby food for most plant seedlings. An orchid seed must meet up with its preferred species of fungus in order to obtain the necessary nutrients for germination.
The network of partnerships between plants and fungi is a hot topic in forest ecology. Some scientists and science writers refer to this mycorrhizal network as the “Wood Wide Web.” We are learning that many plant species in the forest, from trees to orchids, plug into the underground network of fungi for supplemental nutrition and for a means of communication. The more we learn about life on our own planet, the less far-fetched is the neurally networked ecosystem of the (fictional) moon Pandora in John Cameron’s film Avatar.
The orchids of the Blue Ridge are a window into this underground network of fungi-plant relationships. The orchid-fungus relationship is a big reason why orchids rarely survive transplanting and prompts the No. 1 rule of orchid hunters: don’t dig orchids! Simply enjoy them where they are and photograph them all you want.
It appears that each species of orchid has particular fungal partners, so a forest’s selection of orchids mirrors the diversity and health of its fungal community. Since the mycelia of fungi provide much of the underground communications and transportation infrastructure in a forest, an abundance of orchids may be viewed as an indicator for good soil health and biotic diversity.
The mid- and late-summer orchids that are expertly camouflaged against the forest floor are coralroots, twayblades and cranefly orchids, but we do have several showy and brightly colored varieties as well. The popular ones bloom in the spring: the showy orchis and the pink and yellow lady’s slippers. This time of year, we have the spectacular yellow fringed, the graceful ladies’ tresses and the fleeting three birds orchids.
I recently learned about a syndrome suffered by some fans of Avatar. Apparently, some viewers were so taken by the depiction of life on Pandora that they fell into a depression, let down by their own mundane surroundings on Earth. If you suffered from that malady, you should know that you needn’t wait for Avatar 2. Go on an Appalachian orchid hunt. As you gaze into the little mountain masterpieces, marvel at the astounding connective tissue of the forest under your feet.
Burnsville resident Tal Galton is a naturalist who loves introducing people to wild places. He runs Snakeroot Ecotours in Yancey County.