The Ghost Plant: Monotropa uniflora

Jan Thornhill

Any day now—if it ever rains here in Ontario—a most peculiar character will start poking out of the ground in the forest beside my house. The Ghost Plant or Indian Pipes, known as Monotropa uniflora to the scientific community, confuses people every year. No part of it is green, which means it has no chlorophyll, so obviously it's not a plant, right? 

Wrong.

Monotropa uniflora flower close up. (Walter Siegmund)

Monotropa uniflora is, indeed a plant, but it has evolved into an entity that no longer needs chlorophyll to produce energy for itself. Instead, it steals energy from other plants—specifically from trees. It does this in a tricky, roundabout way by joining its roots with the mycelia of mushrooms that, in turn, are networking symbiotically with the roots of nearby trees. The Ghost Plant is a parasite. The mushrooms involved, are not.

This Russula could unwittingly be aiding a parasitic Ghost Plant.

Many species of forest fungi have symbiotic relationships with trees. Their mycelia—networks of root-like threads—intertwine with a tree's roots, helping the tree obtain water and essential minerals from the soil. In return, the fungus receives the energy it needs to grow in the form of sugars from the trees. Both parties benefit. 

The Ghost Plant, which can't provide food for itself through photosynthesis the way chlorophyll-producing plants can, sneakily takes advantage of the relationship between a mushroom (usually a Russula species) and a tree by tricking the mushroom into forming a mycorrhizal relationship with its own roots. In this way, the Ghost Plant receives photosynthetic energy without doing anything at all. It's a total freeloader. The mushroom gets nothing in return, nor does the tree, but no one is harmed in the process, so feel free to enjoy this spooky looking oddity next time you come across one in the woods.

A pink Ghost Plant grows in western North America. (Stephanie Searle)

References:

The Ghost Plant as Tom Volk's "Fungus" of the Month

Mycorrhizas on Tree of Life