Tuesday, July 20, 2021

Monarchs and a Mid-Summer Multitude of Wildflowers at the Barden

So, I was at the Barden today, that being the Botanical Art Garden in Herrontown Woods, and amidst all the positive energy of budding flowers I had a cynical thought. There are a couple spots around the Veblen Circle of wildflowers where milkweed has been spreading. Lots of leaves and none of them being eaten by monarch caterpillars--an all too common observation over the years. People say to plant milkweed to help the monarchs, but the monarchs aren't helping themselves to the milkweed. What gives? 

As if on cue, a monarch appeared an instant after I had that thought. Only the third I'd seen this summer, it was checking out the milkweed and other plants growing in the sunny openings of the Barden. There are many kinds of native flowers blooming right now, which I'll show photos of later in this post, but the monarch headed over to one in particular,

a buttonbush, whose tiny flowers form the shape of a golfball--a convenient surface upon which the pollinator can go from flower to flower, sipping nectar. For an insect it must be like an assemblage of Hold the Cone miniature ice cream cones, but no need for a freezer. 

Moments later, another monarch butterfly caught my eye, and this one was showing a more intense interest in the milkweeds. There are two types at the Barden--purple and common. Both kinds spread underground, creating clones with many stems--enough to support a whole gang of hungry caterpillars. The butterfly was landing on the edge of the purple milkweed leaves and dipping its abdomen under the leaf to lay an egg. 
After doing this a number of times, it headed elsewhere, allowing me to take a look. Not easy to see. There, in the lower left. 
Here's an egg a little closer up.

There's actually quite a bit going on underneath a milkweed leaf. Here was a whole cluster, which I'm guessing are the eggs of the milkweed tussock moth--another Lepidoptera that can stomach milkweed's cardiac glycosides. 

Of course, it's a hopeful sign to see a monarch laying those single eggs, but we saw this last year, and it didn't lead to any sightings of caterpillars later on. It's possible the eggs are getting eaten by ants and spiders. A complex food web can have its perils, and it's interesting to note that milkweed that once grew in farm fields (in the days before Roundup-Ready corn and soybeans) might have had better monarch survival due to there being less predators in that simplified landscape. 

Still, we can hope that this is the year when the Barden does its part to build monarch numbers in preparation for their perilous flight back to Mexico in the fall.

Another sweet sight today, again not captured in a photo, was the pair of hummingbirds that landed on a wire cage just five feet away. Hummingbirds, in my experience, actually spend a lot of time perching, which makes sense given how intense is their flight. Their presence was the answer to a question overheard at the checkout counter at the Whole Earth Center: "Has anyone seen any hummingbirds?" Like monarchs, they also have to negotiate a difficult migration every year.

Maybe they were attracted to the tubular flowers of wild bergamot, 

or beebalm, or jewelweed.

What follows here is a documentation of all the flowers seen blooming right now in the Barden, as the midsummer diversity kicks in. After all the work of weeding and planting, there's pleasure in simply walking the paths and appreciating all that is growing so enthusiastically. 

There's a lot to document. These signs, created by Inge Regan, offer four species to look for. When learning plants, it's good to focus on a few at a time. 

For those more familiar, we've brought together some 40 species that bloom in mid-summer, some of them shown below. Maybe you can walk the pathways and see how many you can find. We're trying to figure out how to pot up all the excess and make them available to visitors to take home.

To see some of the other species showing their stuff this time of year, click on "read more", below.

Friday, July 09, 2021

Some Early July Flower and Insect Sightings at Herrontown Woods

Though the bottlebrush buckeyes in this photo have been blooming in the Botanical Art Garden (Barden) for a couple years now, this photo could not have been taken last year. The gazebo in the background is a new arrival as of last December, and the pin oak behind it can be seen heavily flagged this year by the egg laying of periodical cicadas. 

Those features were not the reason for the photo, however, which was taken because of an insect that requires a zooming in to see.

The Bottlebrush buckeye blooms attract clearwing moths, which do an excellent imitation of a hummingbird in appearance and flight.

Another plant named for the bottlebrush shape of its flowers is bottlebrush grass, also blooming now at the Barden. The wind-pollinated flowers of grasses and sedges lack color, but can still be appreciated for their shape. Bottlebrush grass is called a cool season grass because it greens up early in spring and blooms before the depths of summer. Many other native grasses are of the warm season variety, like Indiangrass, big and little bluestem, broomsedge, and switchgrass. Dominating tallgrass prairies of the midwestern states, they get a late start in the spring and grow through the summer, reaching maturity in the fall. (Turfgrasses have the same categories, though the grasses aren't native. Most lawns around here are cool-season grasses, with bermuda grass being a warm season grass that turns brown in winter.)

Though many species at the Barden have been planted, narrowleaf mountainmint apparently found its way in on its own, growing along one of the paths.

Necessary for the prospering of these summer wildflowers is an opening in the tree canopy where sunlight can reach the ground. Though people often equate habitat health with trees, we actively remove many young trees in the Barden that would otherwise grow up to shade out all these herbaceous species that insects depend upon for summer sustenance. 

Because of this active management, you can look up from the Barden and see some open sky--rare in Princeton open space lands.

Growing on its own, in what few openings occur naturally at Herrontown Woods, is a very subtle green-fringed orchid, here protected from the deer by a small cage. 

And what's blooming in summer in the deep forest that makes up the great majority of Herrontown Woods? I found this one tiny flower in a stream. Local botanist Elizabeth Horn helped me identify it as Water-pimpernel--Samolus valerandi in the
Theophrasta Family. 

The take-home lesson here is that woodland openings are important for summer biodiversity. Given the lack of natural disturbance by wildfire or the long-gone megafauna, it's up to us to create and sustain it. 

Tuesday, July 06, 2021

The Dragonflies and Damselflies of Rogers Refuge

I still remember the astonishment I felt when I first climbed the observation tower at Rogers Refuge in Princeton, and looked out upon this vista, so unlike anything else in town. This expanse of cattails and wild rice, long valued as a birding mecca, remains a gem primarily due to the work of a small group of volunteers, currently led by Lee and Melinda Varian. Grants from the Washington Crossing Audubon help keep invasive species at bay, and Laurie Larson has compiled the site's history and features at rogersrefuge.org, including lots of bird info and an ecological assessment I did back in 2007.

This summer, Hopewell Valley science teacher Mark Manning and his son are working on a new list for Rogers Refuge, this time of Odonata, a.k.a. dragonflies and damselflies. Mark's knowledge of nature is broad and deep, as became evident during a wonderful walk he led at Herrontown Woods a couple years ago. Below is a preliminary list of species he and his son have found during their explorations this summer. The photo is of a black-shouldered spinyleg.

Rogers Refuge Odonata List as of 6/26/2021-Mark Manning

Ebony jewelwing

Blue-fronted dancer

Violet dancer

Powdered dancer

Blue-tipped dancer

Double-striped bluet

Familiar bluet

Turquoise bluet

Fragile forktail

Eastern forktail

Common green darner

Comet darner

Unicorn clubtail

Black-shouldered spinyleg

Lancet clubtail

Common baskettail

Eastern pondhawk

Slaty skimmer

Widow skimmer

Twelve-spotted skimmer

Painted skimmer

Great blue skimmer

Blue dasher

Eastern amberwing

Common whitetail

Carolina saddlebags


Total: 26

Thursday, July 01, 2021

"Among Trees" Theater Event July 15, and Weekly Yoga at Herrontown Woods

The Friends of Herrontown Woods will be hosting its first ever outdoor theatrical event, "Among Trees"--an evening of songs, scenes, and more--next to Veblen House in Herrontown Woods on Thursday, July 15 at 7pm. The event is free and all are welcome. Actors of some renown, Vivia Font and Ben Steinfeld, are organizing the event, which is co-sponsored by the Friends of Herrontown Woods and Princeton Public Library with additional support from The Lewis Center for the Arts and Small World Coffee.

Submissions of scripts are also welcome, due by July 5. Here is the actors' submissions request:
Share a short piece of writing (scene, poem, passage)--in english or espanol--on the Herrontown Woods, trees, nature, or conservation and if selected, have it performed by professional actors in a live celebration of nature and space at the Herrontown Woods in Princeton, July 15, at 7pm. Email submissions to amongtrees2021@gmail.com. Submissions accepted through July 5.

WEEKLY YOGA CLASSES: On July 3, Gemma of Gratitude Yoga will begin leading weekly yoga classes at Herrontown Woods next to Veblen House. The classes will be on Saturdays at 11am, and are free.  Registration is encouraged. All donations will go to support the work of the Friends of Herrontown Woods.

Spotted Lanternflies at the Barden

While periodical cicadas have been the most noticeable insects at the Botanical ARt garDEN in Herrontown Woods, the nymphs of spotted lanternflies have been congregating quietly on a few select plants. Our observations confirm what's widely stated, that the spotted lanternflies prefer to spend their quality time on Ailanthus, also known as Tree of Heaven, a tree introduced long ago to the U.S. from Asia. 

I've been going around, cutting the sprouts of the Ailanthus in an effort to at least discourage the lanternflies' favorite plant.

Another asian species, the ever so spiny Japanese aralia, is also attracting a few of the lanternfly nymphs, but not nearly as many. That, too, gets cut to the ground.
Princess tree had none, though it too hearkens from east Asia. You may notice this species making dramatic, large-leaved root sprouts along the canal and elsewhere. Scroll down at this post about towpath wildflowers to see a photo of a princess tree's root sprout's improbable growth.

All three of these nonnative species persist in the Barden as sprouts that we cut down. It would be nice to think that reducing the number of ailanthus and Japanese aralia will discourage the lanternflies as well. 

Among native species the spotted lanternfly is attracted to, a friend has a grape vine that is attracting a lot of lanternflies. She tricks the nymphs into jumping into bottles of soapy water. 

Here's a post from last August with more info on the lanternflies