Showing posts with label towpath. Show all posts
Showing posts with label towpath. Show all posts

Friday, June 19, 2020

Towpath Nature Trail Loop in Late Spring

It's good to see a nature path well used and free of obstructions, which is the current state of the nature loop that winds through a wide section of the DR Canal State Park, just up the towpath from Harrison Street. (for posts showing the trail in different seasons, type the keyword "loop" into the searchbox for this blog) The whole area was being mowed until I convinced the state park folks to let the wildflowers grow, back in 2006. They then created a nature trail loop through the open woodland landscape between the canal and Carnegie Lake, and maintained it beautifully until a couple years ago, when they asked Princeton University to take over the mowing of the trail. PU actually owns the land, even though it's part of the state park, and they finally agreed to maintain the trail. I was out there with a chainsaw, doing what I could during the transition, given the tendency of trees to fall across the path.

As of June 2, the path was looking great, possibly due to university care, but thus far maintained more by foot traffic than anything else. Here's a plant-person's take on the interplay of native and non-native species to be found along the way.

Common milkweed is one of the few natives that can compete with the highly invasive mugwort. Both spread underground.

Bittersweet nightshade blooming on the shore of Lake Carnegie.

Blackberry flowers, with the green beginnings of the berry emerging as the petals fall.

Here, for comparison, is multflora rose, a nonnative shrub, more common than blackberry, with larger clusters of flowers, curved thorns, and lacking the linear grooves on the blackberry's stem.

Orchard grass blooming. Non-native but not very aggressive, often found as a single, erect clump here and there.

The orange-tinted remains of last year's broomsedge, which is not a sedge but instead a native grass, here lining the trail. Like other native prairie grasses, broomsedge is adapted for periodic fire, which its persistent stems encourage. A field of broomsedge can be very pretty after it turns color in the fall, though farmers associate it with poor soil.

Learn to recognize poison ivy in all its forms. It often looks glossier than other plants with three leaflets, reddish when young, with traces of red remaining in the stem later on. The pair of lower leaflets often show a "thumb" along the lower edge, a subtle version of which can be seen here in the mature leaf. People are surprised to learn that vines like poison ivy only bloom when they find a tree to climb up.

This is a hopeful sight for any lover of Joe-Pye-Weed, which will ornament the trail later in the summer in the patchwork of shade and sun beneath the scattered trees.

One of the dogbanes, which like milkweed will exude milky sap when you pluck a leaf.
Look closely at the photo below of Viburnum shrubs, and you'll see that the leaves of the one on the left are more distinctly toothed. That's the native arrowwood Viburnum (V. dentatum), while the shrub on the right is linden viburnum (V. dilatatum), a nonnative that has become surprisingly invasive in local preserves. As often happens, the native is seldom encountered, while the non-native is common, most likely due to deer preferring to eat natives.

If you know your plants, then you'll look at this small clump of leaves and feel happiness at all the yellow, cone-shaped flowers cutleaf coneflowers will produce later in the summer.

And even happier when you find a large congregation of cutleaf coneflower rising like a very slow-motion firework that will explode in color a month from now.

But knowing plants also allows you to foresee less auspicious trends, as the porcelainberry (NJ's kudzu wannabe) begins to grow up and over most everything in a smothering embrace. Persistent emails have yet to convince the university of the need to mow the field once a year in late winter, like state parks used to do. Annual mowing is the key to sustaining this open woodland of scattered trees lording over a vista of wildflowers.
There's a little parking just across the Harrison Street bridge. The trail loop is on the Princeton side of the towpath, just in from Harrison, with what looks like a birdhouse at the trailhead. Returning via the canal, I happened to see this yellow iris (I. pseudacorus), framed in the trees' reflection in the canal. The native iris sometimes seen is blue.

Sunday, August 13, 2017

Wildflowers and People Gather By the River

What a glorious day, this past Sunday, down along the canal in Princeton. Cool, sunny weather drew people to the canal, by boat, foot and bicycle. The sounds of laughter and conversation mixed with birdsong and a generous show of summer floodplain wildflowers.

Boys returned to their Huck Finn roots,

and insects, too, gathered by the river

or bathed in the sun.

Many different species of oak have long gathered along the section of the towpath between Harrison St and Washington Rd, planted back when the university viewed the canal as an ornamental entryway to campus.

Here's white oak, with it's rounded lobes,

and possibly a post oak, with its lobes arranged in the shape of a cross.

Swamp white oak and bur oak have similar leaves, swollen towards the tips, like the bison that used to forage in the oak savannas of the midwest and south, back when mildfire could play through and refresh the landscape.

Not sure what type of oak this is.

It was a day when nature seemed to be moving towards restoring balance. The overly aggressive multiflora rose was getting a humbling dose of rose rosette disease.

One Ailanthus, at least, was being slowed down by the munchings of the caterpillars of the Ailanthus webworm moth.

The adult is the orange patterned insect in this photo.

And a honeysuckle shrub was being hampered by some sort of witch's broom growth.

Queen Anne's Lace was being pretty without taking over.

Introduced knapweeds like spotted knapweed have spread very agressively in the midwest. I've been trying to believe that this Tyrol knapweed will be relatively benign as it spreads slowly along the canal. Here, at least, it's hosting a monarch.

True, the porcelainberry was having its way in one of the openings in the canopy,

and capitalizing on a tree's demise.

Stiltgrass still lines the nature path,

and a Norway maple's dense shade was stunting growth beneath it.

Mugwort framed concrete marker, but hasn't dominated along the canal like it sometimes does in gas line right of ways.

Signs at the Harrison Street crossing warned of hydrilla, an aquatic invasive plant. None of this, however, could break the upbeat mood of a cool, sunny Sunday in late July.

Flowers from earlier in the year were quickly turning into seeds, like buttonbush

silky dogwood,

common milkweed,

One of the ornamental cherries planted by the university long ago,


and tall meadow rue.

Seeing native shrubs like this elderberry trying to grow along the banks of the canal, I long ago envisioned managing the banks for native shrubs that could beautify and provide abundant wildlife food. But the banks of the canal are managed independently of the towpaths, by a different agency. As with most landscape maintenance, the workers tend to be unselective in what they cut. To preserve the view from the towpath, the bank is cut every few years--not enough time for a shrub to do much flowering and fruiting that would benefit wildlife.

Not far down the lake from Washington Rd. bridge stands the stump of a sweetgum tree once darkened each day by roosting cormorants.

Its life may have been cut short by the excess guano, or its own precarious perch on the edge of the bank. Not sure where the cormorants have gone.

Another sweetgum, with its star-shaped leaves and protruding wings on the branches, was thriving elsewhere along the trail.

Some of the wildflowers have grown to giant size with the well-spaced rains this summer. These cutleaf coneflowers are ten feet high,

as are some of the ironweeds.

The cutleaf coneflowers were the first native wildflowers I spotted ten years ago along this section of the canal, which in turn led to the state park staff reducing the mowing to once a year so these wildflowers would have a change to mature and bloom

Hollow-stemmed Joe-Pye-Weed has really prospered in the open shade of the oaks. Each year there are more patches of these attractive flowers.

Goldenrods can be distinguished by the different shapes of their flowerheads. Some have elm shaped inflorescence,

others are flatter.

Each year, the rose mallow hibiscus bloom along the shore, with lizard's tail and yellow pond lillies extending out into the Carnegie Lake waters beyond them.

It would have been a perfect day to lead what usually is an annual nature walk along the towpath. For 2017, this account will have to do.