Of PEI’s roughly 1,500 species of plants, only seven – less than one half of one percent – have no chlorophyll and can’t make food from sunlight. Over the summer, we’ve looked at three of these oddballs that don’t follow the crowd. Today I’ll add one more: Beechdrops (Epifagus virginiana).
This strange-looking plant could be easily overlooked or mistaken for a dead twig on the forest floor. With no chlorophyll, Beechdrops is not green; with no need to catch sunlight it has no leaves. Instead, this plant is entirely dependent upon American Beech (Fagus grandigolia) – Epifagus literally means ‘upon the Beech’. It taps directly into the roots of these trees, drawing sugars and nutrients that Beech produce through their own photosynthesis.
Beechdrops doesn’t have leaves, but does have tiny, tubular, purple and white flowers that appear in fall. Each plant has two types: some that are self-pollinating and others that rely on ants for pollination. (We tend to think of ants as annoying insects, but they play hugely important ecological roles including seed dispersal, pollination, and protecting plants from pests). Pollinated flowers produce dust-like seeds that are spread by fall rains and spring snowmelt.
In geological terms, Beechdrops is a relatively new arrival to the Island. Our landscape became ice-free following the last glaciation around 12,500 years ago. The pollen record shows that in the millennia that followed, PEI transitioned through lichen-covered tundra, northern spruce-birch-willow forest, and Boreal forest. Pollen from familiar hardwoods such as Beech, Birch, and Maple only shows up about 3,500 years ago.
No Beech means no Beechdrops, but it’s not quite as simple as that. Analyses of genetic data and fossil pollen have shown that Beechdrops’ spread through eastern North America following the last Ice Age wasn’t dependent on the presence of Beech but rather the density. In short, this parasite doesn’t show up until Beech forests are well established and healthy. Not only does Beechdrops not harm its host, it’s considered a sign of a mature forest.
Beechdrops is an uncommon plant on the Island today, much less common than it would have been historically. When European settlers arrived in the early 1700s, about 98% of PEI was forested and Beech was a common tree in the upland hardwoods. Those upland hardwoods had the misfortune of growing on rich soils that were preferred for agriculture; by 1900 the area of forest province-wide had been reduced below 30%, with upland hardwoods taking a big hit. Coupled with this was the arrival of Beech Canker disease in the early 1900s, although I do find Beechdrops in stands that are heavily cankered.
Beechdrops is a good reminder that our native plants don’t exist in isolation. They function as communities, interact with other plants and animals around them (in ways we know about and in ways we don’t), and are essential parts of PEI untamed!
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