There are many reasons to visit Herrontown Woods. Many people walk their dogs there, seek tranquility and relief from a fractious world, or simply want a good hike up to the ridge amongst trees and boulders. Others come to learn the story of the Veblens, as told on the walls of Veblen House. And some are talked into coming by their kids, who want to play and explore in the Botanical ARt GarDEN (Barden for short).
A week later, as someone who stewards and studies Herrontown Woods, I had a much different agenda as I parked my car at a little known entrance to Herrontown Woods, on Windy Top Court.
Through persistent effort in recent years, we've reduced it to little sprouts rising from a massive root system that gets weaker and weaker as we cut and treat the myriad stems, using loppers and a wonderfully frugal, minimalist applicator called a Buckthorn Blaster. We've begun planting native wildflowers in the areas freed of wisteria. Our confidence in this incremental approach arises from success in having freed the Veblen House grounds of a similar massive patch of the vine.
The main target for this two hour solo visit, however, was a new invasive species whose striking fall color in late fall made it easy to spot. The source of the new invasive is a bit of a mystery. Even its name is not certain. We know it's in the genus Pourthiaea, but there's disagreement about its species name. One thing's for sure: it is very pretty in the fall. It is also a threat, smothering and displacing native species as it spreads. If deer and other wildlife reject its foliage, the woods becomes less and less edible over time.
Not everyone has accepted the assertion that Princeton's woodlands have a new invasive shrub/tree to contend with. Some claimed it was a species called asian Photinia (Pourthiaea villosa), which began spreading in and beyond Princeton decades ago. In spring, the new invasive has flowers similar to asian Photinia, but in fall, the asian Photinia turns various shades of yellow and gold--also attractive but strikingly different.
Another item on my to-do list was to take a closer look at a mysterious tree that had been knocked down along the yellow trail. A dead ash tree had fallen across the trail, in the process bringing down another tree that I couldn't immediately identify. Sourwood, I wondered?, remembering a beautiful native tree species from days in North Carolina. Or just a tupelo with longer leaves? Uncanny how the ash had knocked this tree down onto the trail, as if to say, "Look at this!"
A native mapleleaf Viburnums along the trail had turned a special color.
Early November is the time of the color-coded forest, when you can stand in a woods, look around you and identify every plant in sight. Walking down the yellow trail, I spotted a big clump of green amidst a sea of pinkish winged euonymus. What could be so big and still have green leaves this time of year? My guess was bush honeysuckle, a nonnative shrub that has invaded many woodlands in Princeton, but is fairly rare in Herrontown Woods. Wanting to keep it rare, and thinking about how many seeds a big clump like that could produce, I launched into the brush to try to reach it.
The footing was very difficult, because the clump was in the middle of a large boulderfield hidden by the dense growth. Though the nonnative shrubs can turn pretty colors in the fall, their dense growth has blocked many fine vistas and features that we'd like to restore. Each boulder in Herrontown Woods is a work of nature's art, mottled with varied shapes of lichen and moss, like the mottled skin of whales navigating the oceans.
Here you can see the shrubs literally perched on top of the boulders. I cut and treated the bush honeysuckle, navigated back to the trail, and returned down the trail to the car. The nonnatives are not inherently bad. Their rambunctiousness makes them too much of a good thing. Since the deer don't eat them, our loppers play the role. It was a classic session, mixing the satisfactions of stewardship with little moments of serendipity and discovery along the way.
Fortunately, I'm catching this new invasive early, in much the same way we were able to prevent the super aggressive lesser celandine--a big problem in other preserves--from coating the ground of Herrontown Woods in the spring. Vigilance and early intervention are by far the best way to protect the native flora when stewarding 230 acres of public open space.
Also great to see a big patch of a native grass with long, graceful awns on the seeds. Until I can be more definitive with the identification, I'm calling in northern long-awned wood grass (Brachyelytrum aristosum).
