Every group has its oddballs and plants are no exception. Most are content to follow the crowd and make food from sunlight, but a few take entirely different paths. One of those is Pinesap (Hipopitys monotropa).
Excluding hybrids, PEI has about 1,500 species of plants but only seven – less than one half of one percent – lack chlorophyll and are incapable of photosynthesis. Some are parasitic on other plants, but Pinesap makes its living in a more complicated way.
This odd-looking plant is commonly mistaken for a fungus or for Ghost Pipe (Monotropa uniflora), a close relative that uses the same feeding strategy (you can read more about Ghost Pipe here: https://www.pei-untamed.com/post/ghost-pipe). Pinesap is a member of the Blueberry Family (Ericaceae) that differs from Ghost Pipe in its colour and by having more than one flower per plant. It’s much less common on the Island than Ghost Pipe and I was happy to find a big patch in western PEI recently.
When I studied biology back in the 1990s, Pinesap and Ghost Pipe were thought to be ‘saprophytes’: plants that feed on decaying organic matter. We now know their strategy is far more interesting. Under the forest’s soil are networks of fungi that form relationships with trees and other plants. The fungi provide water and soil nutrients to the plants, and the plants provide sugars they make via photosynthesis to the fungi. Pinesap (and Ghost Pipe) tap into this network and steal some of the water, nutrients, and sugars for themselves. Though they have no chlorophyll, they are benefitting from the work of nearby plants that do!
Gaining more energy than you expend is critical for survival, and in this regard not having to make food from sunlight has several benefits. Chlorophyll is a big, expensive molecule to make, and you can save a lot of energy if you don’t need to build it. No photosynthesis means no need for branches and leaves to catch sunlight. (Like all non-photosynthetic plants, Pinesap’s leaves have been reduced to small translucent scales on the stem). Not needing sunlight also means you can grow in the darkest of forests, where there is little competition from other plants.
This lifestyle clearly works for Pinesap, Ghost Pipe, and two of the other non-photosynthetic plants on PEI (the Coralroots, Corallorhizza spp.). The fact that it’s not more widespread suggests that it has its limitations. With the exception of Ghost Pipe, all these plants are rare on the Island and so perhaps finding the necessary fungal partner and right growing conditions isn’t easy. No chlorophyll (or related pigments such as anthocyanins and carotenoids) also means no sunscreen and so these plants are limited to shady forests which are much less common in our region than they once were.
Being green is the preferred option for most plants, but those that take the road less travelled are beautiful and interesting. I’ll show you some other cool examples in future installments of PEI untamed!
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