Why are the orchids here? I park my car along the Class 4 road by a kiosk on Hemenway Road and walk up the trail into our Strafford Town Forest, which had been donated in the 1960s by a local doctor. I feel comforted by the presence of tall old trees of maple, beech, and ash — and a twinge of alertness, as I stop to look up at the claw marks of bears who climb beech trees in fall, fattening up for the winter on beechnuts.

The trail begins its descent after a while into a conifer swamp, and I seem to have entered the Carboniferous Era, with tall cinnamon ferns, delicate woodland horsetails and flowering plants that tolerate the black mucky soils. Marsh marigold, white twisted stalk, swamp saxifrage, red osier dogwood, Joe Pye weed, alder-leaved buckthorn and stunted mountain maples surround me as I step carefully on the slippery boardwalk. Scrawny black spruce trees shade the groundcover of golden saxifrage, three-leaved goldthread, handsome woolywort, and waterside feather moss.

This black spruce swamp lies between the hardwood forest where the bears forage for nuts and the area I have really come to be with — the rich fen where orchids grow and where the bears might come to dig up ant larvae. As I enter the clearing, the muck beneath my feet gives way to spongy, partially decomposed sphagnum moss and sedges. If I were to step off the boards, I might sink up to my knees. The conifer trees here have given way to hoary willow and red osier shrubs. Creeping snowberry and carnivorous sundews crowd onto raised hummocks of sphagnum moss. Red wild strawberries are tiny and sweet. Tall cattails are just beginning to flower, the male and female fuzzy parts that blow apart into the wind are touching each other, for these are native cattails, Typha latifolia. Low marsh ferns Thelypteris palustris have replaced the tall cinnamon ferns. Every plant growing here can survive being wet, or dry, or wind-blown, or baked by the sun. There is fresh nutrient-rich water flowing in and water flowing out. If this were a bog, the only water source would be from the sky; bogs do not flow.

I come to this rich fen to see all the plants, especially the orchids — the white bog orchids, yellow lady’s slippers, ladies’ tresses, purple fringed orchids and the queen of orchids, Cypripedium reginae, the showy lady’s slippers with its large pink pouch-like labellum and white petals, which grow abundantly here in this calcium rich soil. They are a little past their peak, but even when turning brown are still stunning. They are everywhere around me.

If you look at a geologic map of Vermont, you will notice that my town of Strafford sits where two kinds of bedrock swirl together, the Waits River Formation and the Gile Mountain Formation. The first, rich in calcium, the other not so. Fortunately, where I am standing in the fen contains calcium from the shells of ancient marine animals that lived in the shallows of the Iapetus Sea around 500 million years ago. The limestone that formed from their shells, pushed up into mountains as the supercontinent, Pangaea, formed. These old muds have given Strafford, and any other town on the Waits River formation sweet soils, good for hayfields and dairy farms and tall maple trees and, if the conditions are exactly right, orchids.

Orchids are very finicky characters, dependent on their fungal partners to germinate and nurture their tiny “dust seeds,” and dependent on mycorrhizal relationships with other plants in the fen. If one were to dig up an orchid and plant it in the home garden, it would surely die for a lack of friends.

Sexual reproduction of showy lady’s slipper orchids is a wonder, as many orchids, including the showy ladies, offer no edible floral rewards. Pollinators are drawn inside by the flower’s size, colors, fragrance and by the purple spotted pathway into the labellum. To be successful, the bee, beetle, wasp or syrphid fly must be the optimal size, squeezing into the flower so that they are coated with pollen, then exiting the rear orifice, going on to the next same species flower. Too small, and the insect will not contact pollen. Too large, and it will become trapped inside. Some orchid species can self-pollinate, but most do not and have incredibly low reproductive success. Orchids can also spread by underground rhizomes. Showy lady’s slipper orchids are ranked as vulnerable (S3) in Vermont, because of their need for calcium-rich soils in wetlands which are sometimes drained, polluted or built on. They are threatened by deer overbrowsing and by digging by that strange variety of human — the collector.

As I stand surrounded by these pink and white wonders, blackburnian and black-throated blue warblers begin to sing, and I notice the turtleheads and purple fringed orchids will soon be blooming. So many variables have come together to make this day at the fen happen. The ancient muds of sea animals, the continents crashing together into the Green Mountains, the generous Dr. Cobb, the fungal partners of plants of which we know so little, the bumble bees and syrphid flies of just the right size, the purple spotted pathway to the pollen and my own good fortune to live in a place with so much conserved wilderness. I am grateful to them all.

Micki Colbeck is a naturalist and writer and chair of the Strafford Conservation Commission. Write to her at mjcolbeck@gmail.com.