Ephemerrata

I've been indulging in a favorite spring past-time on the way to work, something I like to call drive-by botany.  Even on twisting country roads you have barely a second or two to note a single identifying feature - the form of a leaf, the shape of a tree, a splash of pale white on a blanket of green - before it passes by.  I've gotten really good at picking out spring ephemerals by the roadside and back beneath the  trees at 55 miles per hour, and this is harder to do than it used to be because just about everything else that is leafing out beneath the canopy at this time of year is an invasive species.

So I had to stop the car and stare up in increasing amazement at a hillside covered in Dutchman's  Britches.  I do not exaggerate to say there much have been tens of thousands of these ornate wildflowers, stretching away up the cool, eastern slopes of Sharon Mountain at the entrance to the Housatonic Gorge.  Those gray-green drifts in the foreground are all Dicentra cucullaria, as is everything else in that shade of green heading upslope under the trees.  Dutchman's Britches, so called because they resemble upturned pantaloons, thrive on cool, moist slopes and in conditions where they've been left undisturbed they can become locally abundant.  I've never seen a site before like this, where this species appears to have the greatest share of the biomass.  But looks can be deceiving.

You've probably already spotted the sickly green of Japanese barberry lurking in the shrub layer.  There are some shrub honeysuckles in there too.  But the real threat, the cancer that riddles this site as completely as the Dicentra that still thrives here, is Alliaria petiolata, my old nemesis Garlic mustard.  Every single one of those tiny emergent seedlings in this picture is garlic mustard, which means there's already quite a seed bank here, and it occurs in this density throughout the site.  It is by the roadside, where passing cars, farm equipment and road crews were vectors for its spread.  It is deep in the woods, well established below the ledges, and wherever I found Dicentra, I found plenty of young Alliaria too.

This site had been infested with garlic mustard for a good while.   Management is out of the question.   This is National Park Service land buffering the AT, and while protected from development it is open to invasion and treatment at this stage isn't a realistic option. This moist woodland slope should be filled with spring ephemerals, not only the Dicentra but trillium and bloodroot and indeed I found places like that, but if you click on the image at right - even here - there are garlic mustard seedlings waiting to erupt.

If that hasn't depressed you sufficiently, check out this section of forest a few miles down the road.  Everything you see on the ground that is green is garlic mustard.  I took a walk beneath the trees and here and there I found a native plant.  There was always garlic mustard. Here's a lone trout lily, surrounded by the stuff.  This, too, is protected land, and it is on its way to becoming a biological desert.  Not for everything, mind you.  This is near where I saw the two bears last fall.  But what should be a diverse flora is becoming a monoculture.

Still, I wonder about the Dicentra.  I think I'm looking at a ship that's been holed below the waterline, but maybe it's got a cargo of cork.  The garlic mustard is spread throughout the site but the Dutchman's Britches are still abundant.  There might be an opportunity here for some density plots, to see whether garlic mustard is able to outcompete and ultimately extirpate this native species at this site as it has with so many other plants and other natural communities, or whether the Dicentra can somehow withstand the assault.  I'd like to see what happens later in the summer, when the spring ephemerals have died back and the garlic mustard seedlings no longer compete with them for the filtered sunlight.  I fear I know the answer, but I will stop as I drive by to see.

Comments

[GreenmanTim]

Garlic mustard is really a biennial, overwintering as a basal rosette and then bursting forth in early spring. By late May around here it has reached full height and is making seeds, which it expells in June (30,000 of them) and then dessicates by mid-summer when the damage is done.

[Laura]

I'm only just starting to find the places where wildflowers bloom here locally, early on I saw so much vinca vine (periwinkle) that worried me. Now I see the garlic mustard blooming...

Garlic mustard is a winter annual - so doesn't it go dormant in the heat of summer? The vinca bothers me as I see how it takes over a streambank and covers the ground so fully. It would be some job to pull it all out, but I've thought of getting a few boyscout troops to help in that project.