May in Herrontown Woods

Thanks to Nicole Bergman for most of these photos of a walk at Princeton's Herrontown Woods this past Sunday. The Friends of Herrontown Woods, which I proudly lead, has for the past four years been living up to the expectations stated by the Veblens when they donated this first nature preserve to Mercer County in 1957. The deed calls for "the maintenance of a park, wildlife, and plant sanctuary", and "the stimulation and development of public appreciation of the values of wildlife and plants." Though these are maintenance and education responsibilities the county took on when it accepted this unprecedented gift, we have been doing the work gladly as an expression of civic spirit and love for the charms of this preserve--its intact ecology and fascinating history.

Many of those who came on the walk wanted to hear the latest on our initiative to extend our stewardship to the Veblen House, cottage, barn, corncrib and garage, which also were gifted to the county for public use. The Veblen will states that the house is intended to be a "museum and a library of Herrontown Wood". As with care of the preserve, our nonprofit is ready to fill the void in building stewardship as well, and insure that the buildings continue to be safe and meaningful landmarks in the landscape. With community support, which has already been considerable, we aim to make the Veblen House useful as interior space--a much-needed gathering place in eastern Princeton.

The county's rejection thus far of this initiative, and its frightening move towards demolition, has been surprising in its dismissiveness. For whatever reason, the county chose long ago to put its resources elsewhere than Herrontown Woods. One would think that the organization that filled the resulting void in stewardship, without any government support, would be due respect and gratitude. It's one thing to give short shrift to the expectations stated in will and deed, but another to aggressively oppose those who, in the county's absence, want to realize the Veblens' vision.

The first part of the walk was led by Nicole and Jeff Bergman's son, Jensen, who for a public service project has been helping us build a short loop trail next to the parking lot. We had been thinking of building the trail, but it was the Bergmans' infusion of energy and interest that catalyzed action. Jensen explained that the trail will be a miniature "intro to Herrontown Woods", with plant identification aids, and descriptions of the various habitats the trail moves through. He then showed us the tadpoles and other creatures living in a couple vernal pools near the trailhead.

Farther into the preserve, we encountered Jack in the Pulpits,

Jack being the spadix under the hood or "pulpit". You may remember seeing a spadix in the Peace lily, a popular house plant that's also in the Araceae family.

Wild geranium. Not sure what the linear leaves are that surround it, but they meld nicely into the trunks of trees in the background.

Rue anemone, although it may be more fun to say its scientific name, Thalictrum thalictroides.

If you look closely, you'll see the wings on the stems of this winged euonymus, and also a spot where the deer have been browsing the new growth. Winged euonymus, a nonnative species common in landscaping as "burning bush", has taken over whole hillsides at Herrontown Woods. Like many species that evolved in other climates on other continents, it leafs out early in the spring, casting shade on spring ephemeral wildflowers that need the sunlight to recharge their roots for the next year. Because the deer and insects don't eat the foliage, we've stepped in to serve the role of herbivores, cutting the shrubs down to restore some balance to the forest. Fortunately, the deer have been helping to some extent by eating the fresh resprouts, which perhaps lack the toxins that discourage browsing of older tissue.

We stopped by the cliff to bask in the vista,

then headed to the quarry area. Jensen, demonstrating some mountain goat climbing agility, pointed to a section of diabase boulder ("trap rock") that long ago had been quarried but then left behind. If you click on the photo to see a larger version, you can see the marks along the edge of the main boulder where they hammered in pegs to cleave the rock.

That's yours truly showing everyone an alternate-leaved dogwood, of which only two are known to exist in the park. The more common Flowering Dogwood has opposite branching. The rarity of the alternate-leaved dogwood may have to do with its susceptibility to golden canker, which particularly infects drought-stressed trees. Perhaps these two specimens have held on due to favorable hydrology where they grow.

We then headed over to Veblen House, which serves as a landmark to head towards and gather next to for refreshments and socializing. It's common to think of buildings as useless unless they are made habitable, but we view the Veblen buildings as an inspiring and enchanting presence, useful even now, in their unrepaired state. Four out of five are all already safe and stable. The notion that one has to spend $600,000 to make these buildings useful, as alleged in a recent frontpage Town Topics article on the buildings, has no basis in the realities we've come to know and love through our years of service to the public and the Veblen legacy at Herrontown Woods.

Note: Thanks to the Bergmans for their help, and the photos in this post. Another nature walk the day before at Herrontown Woods is written up at the FOHW.org site.

A Spring Walk Through Herrontown Woods

(This post from 2017)

Update: We had a wonderful spring nature walk at Herrontown Woods on Sunday, April 23. It was Earthday weekend, which is part of Earth Month, Year, Century, and miscellaneous millennia extending out beyond, towards infinite. Earth takes care of people day in and day out, so it's only fair that we return the favor.

Below is a virtual version of the walk along the red and yellow trails past vernal pools and boulder fields, all graced with wildflowers and the babble of brooks this time of year, then past the daffodil-strewn Veblen farmstead and over to the Veblen House grounds for refreshments.

Head down the parking lot to the Red Trail, and the first thing you encounter in spring is the vernal pools that form in the holes left by trees uprooted by storms. It's fun to search the banks of these pools for the well-disguised wood frogs.

It was a weird early spring, with summer-like heat followed by snow-come-lately, but some frogs managed to leave globs of eggs behind. Mosquito wigglers promise a good food source whenever the eggs get around to hatching.

It's proving to be an unusually good year for trout lilies--the yellow flowers with trout-like mottling on their leaves. Most years, one sees abundant leaves on the forest floor, but few actual flowers.

Spring beauty is a more dependable bloomer.

The Yellow Trail branches off from the Red Trail just past the stream crossing, then follows the stream up to a convergence. The opulent leaves of skunk cabbage make these streams a ribbon of green in spring. Take the stone stream crossing to stay on the Yellow Trail.

Here's an impressive lean-to someone built, using the crook of a tree to support the central beam.

Along the stream is some scouring rush (Equisetum), which we discovered on a walk with kids from the nearby Princeton Learning Cooperative. You can pull apart its segments, and use their abrasive silicon texture to sand a clarinet reed, or scour whatever needs scouring. It's a very primitive plant, and small compared to its tree-sized ancestors from the Carboniferous era.

Jack in the Pulpits are getting ready to preach.

Rue anemone lines some sections of trail, giving the impression that the edges of trails offer a particularly conducive habitat, where wildflowers are less impeded by the forest leaf cover.

We may also see wood anemones and Virginia pennyworts. I'm told that the pennyworts have an S2 designation in NJ, meaning S2, which means "imperiled because of rarity (6 to 20 occurrences)". This speaks to how important it is for us to carefully manage Herrontown Woods to protect its diversity.

As the Yellow Trail climbs the slope of the Princeton Ridge, you can see the surrounding understory turning green with, alas, winged Euonymus. That early green flush of species that evolved on other continents can shade out the native spring wildflowers, which depend on that sunlight streaming down unimpeded, to recharge their roots with enough energy to bloom the next year. Native trees and shrubs are slower to leaf out, and so give the native wildflowers the "window of opportunity" they need.

Along the trail, you'll see many of the winged Euonymus were cut. We're experimenting to see if the deer will follow up and eat the resprouts. 

It takes awhile to notice the subtle beauty of flowering sedges.

Mayapples are numerous, though relatively few can be found with flower buds.

Near the top of the yellow trail, before it swings over towards the quarry area and farmstead, is a favorite spot: the boulder field.

A stream flows through the boulders, with enough current this time of year to create a wonderful stereo effect with gurglings of various pitches. These sounds mix with birdsongs, the occasional small plane coming or going from Princeton Airport, and various rustlings of wind and wildlife to create that special seductive serenity of Herrontown Woods. I'd suggest that it was that serenity that drew Oswald and Elizabeth Veblen out to this part of town, and led ultimately to the land being preserved when the Veblens donated it all for public enjoyment.

Here's one of the native shrubs--spicebush--which make subtle, fleeting clouds of yellow in the understory. If the shrubs benefit from an opening in the tree canopy, they get enough energy to make bright red, lipid-right berries for the birds.

Here's the mystery Viburnum. Only a few specimens at Herrontown Woods. There are various natives--V. prunifolium, V. dentatum, and V. acerifolium--and the nonnative Linden Viburnum. But this is not any of those.

Update: Thanks to Henry Horn for putting me in touch with Michael Donoghue of Yale for an ID of this shrub: Tea Viburnum (V. setigerum), a Chinese species "that is escaping and becoming established in several areas in North America."

Part of the charm of Herrontown Woods is its farmstead (photo below), which includes a small red barn and corncrib, and the shingled 1875 farmhouse known as Veblen Cottage. Many people confuse the cottage with the Veblen House, which is a couple hundred feet away, through the high fence. These daffodils were either planted by Elizabeth Veblen or by one of the local garden clubs that showed their love for the Veblens and Herrontown Woods by caring for the gardens well after Elizabeth passed away in 1974. The daffodils went unnoticed until Friends of Herrontown Woods board member Sally Tazelaar removed all the multiflora rose that had grown over them.

The current owner of these buildings, Mercer County, has taken initial steps that, if not countered, would lead to their demolition. They are in fine shape and remind park visitors of Princeton's farming heritage. Our nonprofit, the Friends of Herrontown Woods, has submitted a proposal to acquire and maintain these buildings with the same love and commitment we have shown by taking care of Herrontown Woods for four years.

Update, April, 2021: The Friends of Herrontown Woods and its supporters convinced the town to take ownership of Herrontown Woods from the county, and lease the buildings to our nonprofit to begin repairs.

Learn more during the walk, and consider getting involved via our FOHW.org website.

Porcelainberry: the Vine that Ate Princeton

Here it's Friday of National Invasive Species Awareness Week, and nary a post about invasive species!

First, readers should be aware that there are contrarians out there, writing books, articles and opeds, trying to deny that invasive species are a big problem. It's fascinating to analyze their mental gymnastics and deceptions, which are similar to those used to deny the reality and danger of climate change. I've picked apart their faulty logic in posts that can be found at this link.

Now, on to our porcelainberry tour of Princeton. You won't find it in shady areas, where other invasives like stiltgrass, garlic mustard and winged euonymus thrive. Rather, porcelainberry threatens to smother all of those sunny openings and edges that shade-intolerant plants depend on for survival. Porcelainberry is related to our wild grape, but much more aggressive. Your first impression will be, "What lovely multicolored berries!"

Your second impression, as it climbs up the stems of your shrubs, like this elderberry, might be, "Oh, a little rambunctious, but those berries are so pretty!"

Your third impression, as it turns your yard or park into a monocultural topiary, will be more along the lines of, "OMG! HELP!" No, this is not kudzu growing along a freeway down south. This is porcelainberry winning a modern day Battle of Princeton, with stealth and persistence far beyond anything we distracted humans might muster.

This is what a nearby patch looks like in December, just down the road from the Princeton Battlefield, along Quaker Rd between Mercer and 206. Invasive vines and shrubs can seem less overwhelming in winter, which is actually a good time to remove them. In spring and summer, though, all that growth energy can be intimidating.

And this is what porcelainberry is doing to the sunnier portions of our lovely nature trail off the DR Canal Towpath near Harrison Street. The blackbirds may say hello to the berries, but it's bye bye to the diversity of native wildflowers underneath that foliar blanket.

Turns out porcelainberry's a soccer fan. Here it is in the cheap seats at Princeton University's Roberts Stadium, at one end of the field,

and at the other.

Here it is (light blue and pink berries) in that "second impression" stage, climbing over a honeysuckle shrub (red berries) at Quarry Park. Give it a few years and it may reach the "OMG" stage.

I haven't seen much of it in eastern Princeton yet, but we'd be smart to keep an eye out and remove it before the berries mature.

Otherwise, sunny edges everywhere will look like these hapless flowering dogwoods, planted at Princeton Battlefield in 1976 for the nation's bicentenial, and now struggling to survive beneath a spreading blanket of porcelainberry.

Note: You can help liberate the dogwoods from the porcelainberry and other vines on Saturday, April 1 at 1pm. I've been collaborating with the Princeton Battlefield Society on invasive species work for the past several years, and will be leading a group to preserve the dogwoods that line the field on the north side of Mercer Street.

Another group of volunteers will be continuing the multi-year effort to reduce the bamboo clones near the Clark House, which we're actually having considerable success without herbicide. 

For purposes of identification, here are a couple closeups of porcelainberry. The berries are distinctive, with different shades of blue, red and white.

The leaves are easily confused with wild grape. This photo shows how variable is the shape.

I hope everyone's having a happy National Invasive Species Awareness Week. We'll end with a short Q and A:

• Are all nonnative plants invasive? No. Nonnative refers to origin. Invasive refers to behavior.
• Why are invasive plants invasive? Oftentimes, it's because the native insects/deer, etc don't eat them, giving them a competitive advantage. To regain the balance we lost by introducing species that evolved elsewhere, people end up having to be the herbivores, wielding saws and loppers.
• One nice thing about invasives? They get us out in the woods for workdays. 

DR Canal Nature Loop in Winter

The DR Canal State Park crew hasn't yet done its annual mowing of our little nature trail, next to the towpath just upstream of the Harrison Street bridge. That means we can do a little virtual February nature walk. (Summer tour at this link.) Some background info: The land here, bounded by the Washington Rd and Harrison Street bridges, the canal and Carnegie Lake, is owned by Princeton University but maintained by the DR Canal State Park. Back around 2006, having seen native wildflowers getting mowed down, I convinced them to shift from weekly to annual mowings of the areas away from the towpath. The annual mowings keep the meadows from growing up with trees. They then created this nature loop through the open woodland with sunny patches of wildflowers and views of Carnegie Lake.

It starts with a nice sign and box for pamphlets that I need to refill.

On your right is a stand of switch grass--one of the grasses of midwestern and plain state prairies that also grows in the east. Switch grass is one of the native grasses that grows erect enough to fit in as an ornamental in people's gardens. It got its two seconds of fame in a president's 2006 State of the Union address, as a potential source of ethanol.

Left of the path are the remains of an evening primrose's seedheads, held high.

A short way down the trail is a cluster of red oak leaves. Follow the branch back to the trunk of the tree,

and you can see that the beavers have been busy.

A little farther is a bench looking north across Lake Carnegie.

A closer look at what's growing there along the shore shows the remains of last summers native hibiscus blooms (Hibiscus moscheutos). Kayakers heading upstream on the Millstone River from Carnegie Lake in midsummer will encounter this showy wildflower lining the banks in some sections, its feet in the water.

The bench, by the way, was donated in memory of Anuita Margolis Blanc. An internet source says she founded the Nassau Cooperative Nursery School, was president of the Princeton Assn. for Human Rights, president of the Princeton Study Center, and founder and partner of Princeton Crossroads Realty.

Here and there you'll see the seedheads of ironweed, a tall reddish native floodplain wildflower that blooms in later summer.

Also on the left are some clones of Indian hemp, related to milkweed.

Pin oak has narrower, more deeply lobed leaves than red oak. There are lots of different oaks along the pathway, including a bur oak, which is more of a midwestern species--evidence that at one point the university planted this area to ornament the entry into campus from Route 1.

Broomsedge, actually a bluestem grass, grows along the right edge of the trail. A field of broomsedge can be a beautiful sight in winter, except to farmers who view its presence as evidence of poor soil.

You'll see lots of this--Japanese honeysuckle. Though it's one of the first invasive species I learned about, it cannot compete with the smothering power of porcelainberry, which is now dominating farther down the trail in sunnier areas.

Where the trail turns left and heads towards the towpath before bending back around, there are expanding groupings of Joe-Pye-Weed--one of the native summer wildflowers that has responded well to the annual mowing management.

Look on the ground around there and you're likely to see a "gum ball"--the many-capsuled fruit of the sweetgum tree.

Look up and you'll see many of the gum balls still on the tree.

Goldenrods are thriving. The floodplain species of goldenrod tend to spread underground via rhizomes and tend to dominate over time.

Some trees are "self pruning", but pin oaks tend to hold their lower branches, which bend down in a characteristic way.

Beech trees are related to oaks, and show the similar habit of holding onto their leaves far into winter.

Beyond this bench is a tree that's lost some of its lower bark.

More evidence of beavers.

Here's one of the shrubs left over from the 1960s era plantings by the university--a row of fragrant honeysuckle that sometimes gets on lists of invasive species, though I've never seen it spread. It has small but very fragrant white flowers in late winter. Lonicera fragrantissima is the latin name.

The remains of a pokeweed bloom.

That gets you about halfway down the path. It circles back over to the towpath. The Delaware and Raritan Canal State Park has programming during the year.