Wednesday, June 28, 2023

Sedges Have Edges, and the Blessing of Wet Ground

Sedges are an acquired taste that, once acquired, deepens the pleasure of botanizing. They are grasslike plants that show their beauty not through color but through architecture. Many of them flourish in wet ground. Perhaps the most famous sedge is papyrus, which we were all taught was used by the Egyptians to make paper.

In New Jersey, we have lots of native sedges. One of my favorites is the fringed sedge (Carex crinita). I planted one in the mini-raingarden in front of the Whole Earth Center, along Nassau Street. I guess it looks like a grassy blob, but if you look more closely, 

you'll see it has these pendulant clusters of seeds that look like fingers. The fringed sedge's graceful aspects disguise the toughness at its root, so to speak, as it holds fiercely to the ground. That and its capacity to thrive in wet ground makes it very useful for stream restoration projects.

To distinguish a sedge from a grass, take a close look at the stems, which aren't round like a grass but instead are triangular in cross section. "Sedges have edges" is a fun way of describing the stems. Roll the stem between your thumb and forefinger and feel the edges. Some sedges have more rounded edges than others.

In a much larger raingarden that I manage, over in Smoyer Park, there's a massing of sedges that look like a sea of grass with little pompoms on top. I had been repeatedly forgetting the name of this one, so I was happy to see my "Seek" app (a version of iNaturalist) identify it as squarrose sedge (Carex squarrosa). 
Sedges, like all plants, encourage you to look closely and make fine distinctions, which can help your thinking in other aspects of life. This one probably looks a lot like the squarrose sedge, but the seedheads are a bit heftier. My Seek app is calling it hop sedge (Carex lupulina), which I'll go with. We botany types are often in our own orbits. It really is transformative to have a fellow botanist in the form of a cellphone to carry around in your pocket.

This one has elongated seedheads in clusters. I'll call it sallow sedge (Carex lurida). 
Another sedge I've been dividing and moving to new locations--in my front yard and at the Barden in Herrontown Woods--has distinctive seedheads that look like stars. Having enjoyed calling this morning star sedge, I was surprised to find Seek calling it Gray's sedge, but these are just two common names for the same plant, Carex grayi.

There are other sedges that you're likely to encounter if you gravitate like I do to wet, sunny places. Green bulrush and woolgrass are sedges that were obviously named by people who couldn't tell a sedge from a rush from a grass. Feel the edges, people. 

So-called woolgrass is one of my favorites. This photo was taken at the Barden, later in the season, after it has developed its wooly inflorescence. Unlike most sedges, which mature early in the season, woolgrass grows taller and over a longer arc of time, with attractive features at each stage of development. 

One sedge you're less likely to encounter is tussock sedge, which I've only seen in a springfed marshy area of Mountain Lakes that is unfortunately inaccessible via existing trails. 

Often contrasting beautifully with the light-green leaves of sedges is the deeper green of soft rush (Juncus effusus), which here in the Smoyer Park detention basin has achieved a lovely vase-shaped form decorated with pendulant clusters of seeds reminiscent of earrings. I've seen soft rush used as a striking specimen in gardens--not bad for a native plant that mostly hangs out in ditches and other low ground. 

Sedges have edges; rushes are round, meaning that rushes have rounded stems.
Another reason I like sedges so much--along with other plants they associate with in wet, sunny places, like this Hibiscus (moscheutos)--is that so many native plant species thrive in wet ground and full sun. That, and the soft ground that facilitates weeding, makes for less work and more time to gaze across the expanse and appreciate the beauty. 

Tuesday, June 13, 2023

Poison Hemlock Popping Up in Princeton

When mathematician and Herrontown Woods volunteer Robert Budny reported that he had found lots of poison hemlock growing in his yard in Princeton, I was at first surprised. I somehow got it in my mind that he was talking about water hemlock--a rarely encountered native wildflower, of which I have come upon a grand total of one growing in Princeton's preserves. 

Robert was quite sure of his find, and said he'd experienced skin irritation while cutting the numerous plants down.

Then I saw this patch of white along Snowden, which too was surprising, since I pass there almost daily yet had never noticed before these tall plants covered in blooms. Maybe it was Robert's sharing of his backyard encounter that primed my eye to take notice.

These, too, proved to be poison hemlock, with broad disks of tiny white flowers. 

and lacy compound leaves. Other plants with white disks of flowers this time of year are the shrubs elderberry and silky dogwood, but they don't have finely dissected leaves like this poison hemlock. 

Though Princeton has many invasive species, those in the carrot family have been few. Goutweed spreads through some gardens. It gets mixed in with the intended plants and can be very hard to eradicate. My neighbor up the street was somehow able to do it, though, through sheer persistence. Wild carrot (Queen Anne's Lace) shows up occasionally along roadsides. It's a beautiful plant, but I've seen it become too much of a good thing in the midwest. Here's information on which members of the carrot family behave invasively in Wisconsin. It includes a useful description of this plant family.
"Many members of the carrot family (Apiaceae) are invasive in Wisconsin. These herbaceous biennials and perennials have alternate, compound leaves with sheaths at the base of leaves. Many small, 5-petaled flowers are arranged in compound umbels (several small umbels combine to make larger umbels). Of the species that are invasive, all have white flowers except wild parsnip, which has yellow flowers. Seeds form in pairs and stems are hollow at maturity."
There are other invasive plant species that, entrenched elsewhere in NJ, are just starting to show up in Princeton. Jetbead and Mile-a-Minute are examples. Catching these early and preventing them from spreading means fewer aggressive plants for gardeners and preserve managers to deal with in the future.

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Tuesday, June 06, 2023

PHS Ecolab Wetland Update -- Early June

The Princeton High School Ecolab wetland continues to bounce back nicely from its surprise defoliation last fall. 

If you pass by, you'll see the cattails that we're hoping to keep contained in one corner. The cloud of gray-green beyond is an annual grass planted by contractors as a cover crop, dotted with the deeper green of all the pre-existing native plants now re-emerging from their roots.
The ponds have water, despite the extended drought--sign that the sump pumps are now functioning again, delivering water from the school's basement up into the wetland. 

If you look a little closer, you may see some native blue-flag irises still blooming, happy as clams in this wet world.
On drier ground, the common milkweed is about to bloom.
Bindweed, in the morning glory family, is advertising its location. It's a non-native vine that is too aggressive. While I went around pulling it out (if we could use herbicide, we could kill its roots and be freed of an ongoing task), I checked to see what other plants are rebounding. 
Joe Pye Weed is back, as is fringed sedge.
Good to see boneset and Hibiscus popping up. They don't look like much now, but a (wild) gardener can see the promise in these little nubbins.
It can be a challenge to distinguish a blackhaw viburnum sprout from
silky dogwood. Both of these, along with elderberries, will grow back from their roots to become big shrubs. Since trees become oversized for the site, these shrubs will have to do as places for birds to land and hide. Large shrubs will also help curb the expansionist tendencies of cattails. 

We'll see how the lack of shade, now that trees have been removed, will affect the balance of the various species. Some plants like cattails and lizard's tail may spread more aggressively now that they are in full sun. But overall, the rebound is looking good.