An Appalachian Fungus Thief
Bentley's Coralroot, Corallorhiza bentleyi, is an orchid that contains no chlorophyll and does not perform photosynthesis. Instead, it is a full-time parasite, stealing all of its nutrients from fungi in the soil. This lifestyle is called mycoheterotrophy. The orchid's underground rhizomes—branching, tuberous structures resembling sea coral, are the source of its "coralroot" name. These rhizomes interface with a specific fungal network to survive. Research indicates an extreme specificity for fungi in the genus Tomentella, particularly Tomentella fuscocinerea. This three-part system involves the fungus, which gets its own energy from the roots of nearby trees, the trees themselves, and the orchid that taps into the fungal network.
The visible portion of the plant is a single, leafless flowering stalk that emerges from the forest floor, typically reaching a height of 20 centimeters or less. The stem is a reddish to yellowish-brown color. It produces an inflorescence called a raceme, which can hold up to 20 small flowers. Each flower's lip, or labellum, is unlobed and measures about 5.7 to 5.9 millimeters long, often marked with three prominent reddish-purple veins that guide pollinators. One characteristic of the orchid is that its flowers are frequently cleistogamous, meaning they are capable of self-pollinating without ever opening.