Some plants get all their energy from parasitizing fungi instead of regular photosynthesis

Most plants, including most trees, gets most of their energy from photosynthesis. In this process, they use the carbon dioxide in the air to create carbohydrates that they use for energy, while also creating oxygen as a by-product. Despite this being the main source of energy for most plants, some plants have completely different strategies to get energy, such as the one we will be discussing today.

A few plant species do indeed get all their energy from a symbiotic relationship with a fungi mycelium, such as Monotropa hypopitys or the orchid Neottia nidus-avis. Like all plants they form mycorrhiza with one or more fungi. Usually this is a two-way relationship where the fungi gets carbohydrates, while it gives the plant other nutrients such as metals and other stuff that is found in the soil. However, with these myco-heterotrophic plants the symbiosis is parasitic, and the plant leeches nutrients from the fungi, including carbohydrates.

Monotropa hypopitys, a myco-heterotrophic plant I often find when walking in the forest. It's not very rare, but I still only find it 4-6 times yearly, so it's not really common either. Image by @valth.

Since these plants don’t make their own carbohydrates, they don’t need to use energy on creating chlorophyll. This makes their physical appearance looks pretty weird, because we are really expecting all plants to have some part of the structure filled with the green chlorophyll. Instead these myco-heterotrophic plants tend to be white or just pale colored, since they don’t have any chlorophyll. Their flowers can still have bright colors to attract insects, but they will generally not bother to spend energy on changing the color of their leafs or the stem.

In addition to the obvious advantage of not having to get your own food, there are also some other bonuses to being myco-heterotrophic. One of these major advantages is that these plants can grow in places that have constant shade where photosynthesis would not be possible. This area might have a very good supply of nutrients in the ground since there are no other plants nearby to share the nutrients with, making it an ideal place to settle down for a non-photosynthetic plant. For this reason we can sometimes find these types of plants in really shaded areas where it's literally the only thing that's standing up from the ground. I often find Monotropa hypopitys in places that have extremely thick foliage cover from pine trees.

In addition to having obligate myco-heterotrophic plants that get all their energy from the fungi, there are facultative (partial) myco-heterotrophic plants that uses the fungi as a secondary food supply, while still having photosynthesis. Some orchids are also facultative myco-heterotrophic during parts of their life cycle, and changes to regular photosynthesis once they’ve grown bigger.

As I said at the beginning, most of all plants have a symbiosis with fungi where the fungi acts as an extension of the roots of the plant. The big difference between this mycorrhiza and the myco-heterotrophy is that in the mycorrhizal symbiosis, the flow of carbon is from the plant to the fungi, and the other way around for the myco-heterotrophic plants.

Thanks for reading

Thank you for taking a look at my post about the myco-heterotrophic plants that steal carbon from the fungi in the area. I hope you learned something new, and if you’re lucky you might see one of these plants this summer! Please leave a comment below if you got any questions.