By David J. Hawke -- Over the past few months, more than 500 species of local flowering plants have put forth their blossoms in hopes of creating seeds for future generations of itself. As we slip into late summer the last on the list of wildflowers have been producing flowers and seeds at a great rate.
The most obvious of these late bloomers are the asters and goldenrods, an admittedly confusing mix of glorious genetic varieties. You can enjoy them at their face value as a lovely palette of pre-autumn colour, or you can dive deep into the minutia of identification features to determine one species, or variety, from another.
The flowering species that most defines summer’s end for me is the oft overlooked Virginia beechdrops. The plant is found only within mature forests that contain large and stately American beech trees. We are fortunate to live in eastern North America, as this is the only place that beechdrops are to be found.
As its name implies, beechdrops have a close association with beech trees. To find beechdrops you must first find a beech tree (however not every beech tree will have beechdrops growing under it). Look for a tree with bark that looks like elephant skin, smooth and grey. Then look for a woody stem of what at first appears as a tan-coloured dead stick rising up to just below knee height. A closer inspection might reveal the delicate white and maroon striped blossoms (if there are no blossoms you may have simply found a dead stick; try again).
Now for some fascinating facts about this wildflower: it contains no chlorophyll nor leaves, and is therefore incapable of photosynthesis. The majority of plants have leaves packed with green chlorophyll that absorbs sunlight and through a magical process transforms that solar energy into starches and sugars that provide food and growth proteins to the plant. Not so with beechdrops.
These flowers have devised a way to obtain growth materials from another plant, in this case from beech trees. There is a small group of these “no chlorophyll” plants and they are all parasitic on a specific host. Bear corn (formerly called Squawroot) attach to oak roots, ghost plant (formerly called Indian pipe) prefer white pine, pinesap (still operating under this name) also to pine tree roots, and so it goes.
Parasitic plants take what they need and offer no mutual benefit to the host plant. This is unlike fungi which takes nourishment from tree roots yet in return provides dissolved elements taken from the soil. Although parasitic, beechdrops do not harm the host tree.
The flowering stem of beechdrops has two types of blossoms, the lower ones being closed and self-pollinating, the upper ones appearing as a normal flower yet often sterile (lacking pollen). The lower flower buds mature and create hundreds of dust-like seeds that are released in autumn or early winter.
These tiny seeds are distributed by heavy rains or the heavy runoff of springtime snow melt. They must land near a beech tree to obtain a chemical produced by the tree that stimulates germination. At first the wee small seedling will live underground, sustained by the nourishment provided within the seed. Eventually the flower’s tiny roots will find and penetrate a rootlet of the beech tree.
It may take several years before the wildflower is strong enough to produce a flowering stalk. (Note: some books say that beechdrops are an annual, but this process suggests perennial. Just saying, it’s hard to know what to believe.)
The older and larger the beech tree, the more of the germinating triggering chemical is produced, so big old trees have more beechdrops growing under them than do smaller trees.
But then we find there is another limiting factor that is in play… the beech trees are all dying off. For a couple of decades, a fungus called beech bark disease has swept through southern Ontario and has killed about 98-percent of the existing mature trees. As the big trees die off, so too do the parasitic beechdrops.
There is an interesting twist to the die-off of the beech trees, in that the species is not being eliminated, only the mature trees. This is similar to the loss of the American elm trees in the 1960s, when row after row of the stately elms died off within a few years of Dutch elm disease. It is now evident that both elm and beech are surviving as a species, as young trees that are being produced from sucker growth from existing root systems.
This type of reproduction will produce mostly sterile plants that will rarely get to grow as large as their parent. About the time these young beech or elm break through the sub-canopy of the woodlot, the fungus will find, attack and kill the upper parts of the young tree.
As stated, beechdrops thrive when growing in proximity to large beech trees; does the demise of large beeches mean the demise of the associated wildflower? Perhaps. The beech trees are now showing in our woodlots as bushy shrubs, with numerous stems emerging from the dying roots of the old tree. This low and dense growth is creating a shift in the ecosystem of the forest floor due to heavy shading and low dense growth of leaves.
Although the beechdrops don’t need sunlight and can survive in heavily shaded areas, will the young beech clones (I guess they could be called sons of beeches) provide the chemical required for the wildflower seeds to germinate?
As you take a late summer wander through the local woodlot, keep your eyes open to fins a stand of beechdrops. It may soon be but a memory of what once was a healthy forest.
Dave’s Notebook: Lots of late summer/early fall things going on outside... just wear a raincoat... and sweater.... and warm hat.... and gloves.... and rubber boots. Enjoy!
© 2021 David J. Hawke