A Thief in the Forest
Deep in the humus of coniferous forests across the Pacific Northwest, a strange plant pushes its way into the shaded light. Allotropa virgata, known as candystick or sugarstick, looks like a misplaced piece of holiday candy. Its leafless stalk, growing up to 50 centimeters (about 20 inches) tall, has bold vertical red and white stripes. This plant is a mycoheterotroph, a type of parasite that has abandoned photosynthesis entirely. It contains no chlorophyll, the green pigment that allows most plants to create their own food. Instead, it survives by stealing nutrients from its neighbors, and its target is not another plant.
The candystick's existence depends on a three-part system. It directly parasitizes the underground mycelial network of a fungus—specifically, the matsutake mushroom, Tricholoma murrillianum (often identified as T. magnivelare). This fungus maintains a symbiotic, or mycorrhizal, relationship with nearby conifer trees like Douglas firs, hemlocks, and pines. The fungus helps the tree absorb water and minerals, and in return, the tree provides the fungus with sugars produced through photosynthesis. Allotropa virgata inserts itself into this partnership, tapping into the fungal network and siphoning off the carbon and nutrients that the fungus has acquired from the host tree.