A Special Bluff With Special Flora

There are places in nature that feel special in some way, places we find ourselves returning to. One special place for me is a bluff in the lower valley of Ellerbe Creek--a stream in Durham, NC for which I founded a watershed association a quarter century ago. 

During a recent visit, I took a walk with naturalist Cynthie Kulstad in one of the preserves we created back then, 80 acres called Glennstone Preserve. Cynthie is the botanist/horticulturist who helped sustain many of the plantings I had nurtured in parks and nature preserves while living there. The trails and our inclinations led us down to this special spot, on adjoining Army Corps of Engineers land.

Crowned by a massive white oak, the bluff is a collection of diabase boulders and uncommon plants overlooking the creek. 

One of those uncommon plants that makes this spot distinctive is resurrection fern (Pleopeltis polypodioides), all curled up and dried out on one of the boulders. Resurrection fern is an epiphyte, meaning it builds itself largely out of water and air, pluse whatever few nutrients collect on the rock it clings to from fallen leaves. Unlike most plants, this fern's leaves can dry out during droughts, then rapidly rehydrate after rains.

The only other place I've seen resurrection fern in Durham is on a similar but much larger bluff, where the Eno River just to the north encounters a mass of diabase rock and takes a sharp turn to the right, called Penny's Bend. I sense a kinship between these two bluffs, botanically and geologically. They could be called Big Bluff and Little Bluff, reflecting the respective size of the watersheds they are in.

(Up here in Princeton, NJ, with the same piedmont geology as Durham, a similar relationship can be seen between the big "Roaring Rocks" boulder field in the Sourlands and the boulder field in Princeton's Herrontown Woods, where the boulders are smaller and the water tends to chuckle and murmur rather than roar. These geologic features, too, are composed of diabase rock that resisted erosion through 200 million years.)

Looking up, I spotted another unusual native plant, eastern mistletoe (Phoradendron leucarpum), growing high on a tree branch. This one's a hemiparasite, meaning it extracts some sustenance from the tree but also has green leaves to make some of its own energy.

Other trees nearby also had dense balls of vegetation high up in the branches, but they weren't mistletoe. Those are witch's broom--a dense cluster of twiggy growth that is the tree's response to a pathogen or other irritant. Cynthie pointed out they are common on hop-hornbeam, a tree I hadn't seen in a long time and had been wanting to run into.

Turned out we were in the midst of a grove of eastern hop-hornbeam (Ostrya virginiana), growing along the edge of the bluff. (Upon returning to Princeton, I found some of these with their distinctive bark growing in Autumn Hill Reservation.)

Another tree nearby, judging from the leaves on the ground, was swamp chestnut oak (Quercus michauii). Paul Manos of Duke University calls these "sun leaves," meaning they are leaves that had been growing higher in the canopy and thus received a bigger dose of sunlight. They're smaller, thicker, and with sharper lobing than the more shaded leaves below.

I found more online about sun leaves and shade leaves, in a post by Gabriel Hemery:

"If there is some sunlight however, even a little diffuse light (see below), then a tree makes the most of it by producing shade leaves lower down in its canopy. Shade leaves are larger and thinner than normal sun leaves, and often appear a darker green (they contain more chlorophyll). They also have half as many stomata than sun leaves, or even fewer, and so have a lower respiration rate. They can react quickly to brief bursts of sunlight and dappled shade.

Shade leaves can turn into sun leaves and visa versa; providing that the change is gradual. This is something that a gardener moving a plant outside that has been grown indoors or in the greenhouse, must be aware of. When a plant is taken outdoors, place it first under shade and gradually over several days increase its exposure to bright sunlight." 

It would be interesting to know if pine needles, like those high up on this shortleaf pine, also vary according to how much sun they receive. 

During my eight years in Durham, plus many return visits over the years, I've found many special places along Ellerbe Creek. They could be as simple as a native azalea leaning out over the creek, or as complex and improbable as a roadside embankment packed with more than 100 native species of piedmont prairie. A few have been tragically destroyed, but it's heartening to return to those that persist, their charms sustained, their uniqueness unshattered by a rapidly changing world. These pockets of stability give my soul something to lean on.

Finding Pawpaws in Paw Paw, Michigan

When the Lunar Octet, a latin/jazz band I've been in for 40 years, performed this past weekend in PawPaw, MI, a jazz naturalist like me was naturally curious about whether there are any pawpaws growing there. 

The town, named after the PawPaw River, which in turn was named by the indigenous people after the pawpaw trees that grew along it, has a population of about 3500.  Though the downtown preserves some historic feel, the town has not exactly embraced its namesake. Grapes ornament the town logo on the water tower and elsewhere, not pawpaws. 

Upon arrival, I asked my phone where I might find a pawpaw in Paw Paw, and was directed to the post office, where I navigated past redbuds and callery pears before finding this pawpaw tucked around the side. 

The tree had fruit, but none ripe as yet. I asked around, at the sandwich shop and down along the beautiful lake where we performed. Most people were unfamiliar with this native tree. The post office worker I ran into said he didn't know anything about pawpaw trees in PawPaw, except that he doesn't like the taste. 

The flavor of a pawpaw, a rich, creamy combination of mango, banana and pineapple is appealing to some but not everyone. Our host was more generous with her knowledge and assessment, mentioning a couple places the pawpaw grows in town, including at one of the schools.

The town of Pawpaw sprouted along the Territorial Road, one of the three main east-west routes of pioneer days. That history is documented next to the lake, but the native tree remains largely unknown and uncelebrated in a town that bears its name. 

My theory is that, since Asimina triloba primarily grows in floodplains, the pawpaw trees were lost when the river was dammed to make Maple Lake. Its fruit, with fragile skin and a taste less universally appreciated than other tropical-tasting fruits, resisted mass marketing. That, and the general drift away from plant knowledge, consigned the pawpaw to obscurity. 

Still, it remains a singular fruit, the only member of the tropical custard apple family, Annonaceae, to adapt to northern climates. And some of us still remember the song: "Way down yonder in the pawpaw patch"--a pawpaw patch that, in PawPaw, Michigan, became a lake with a lovely breeze to carry our music. 

Update: Turns out that, if you live in PawPaw Michigan, you'd have to drive to southern Indiana or Ohio to find a festival celebrating the pawpaw. PawPaw's festival celebrates grapes.

Campus Grounds Sprout Local Flora

Some areas of Princeton University's intensely landscaped campus are starting to sprout local native flora. Using native plants doesn't necessarily mean those species will be found in local nature preserves. Many native plants popular in landscaping--purple coneflower, red buckeye, bottlebrush buckeye, oak-leaved hydrangia, witch-alder, Virginia sweetspire--are seldom or never seen growing on their own in the local wild. 

But recently, the University has been planting the actual species frequently encountered in local nature preserves like Herrontown Woods and Mountain Lakes. This spicebush shrub in front of the Lewis Center for the Arts, 185 Nassau Street, resonates with the spicebush  so common in our woodlands.  

 

Turf has been replaced with a sedge meadow, probably the same Pennsylvania sedge that can be encountered in remnant meadows in local woods.

Masses of Christmas fern now grow on campus as they do along the slopes of the Princeton ridge.

A few species, like the foamflower making this mass of white, are rare to nonexistent in local woodlands, but the overall trend seems to be to treasure what is authentically local. 

Though some of the University's early efforts to plant native landscapes became overrun with weeds, this 2-3 year old planting down near Robert's Stadium is thriving. Better soil prep and thick mulch (and more knowledgeable gardeners?) have, at least thus far, conquered the weeds. The native species chosen are again those one finds in the local wild: cutleaf coneflower, arrowwood Viburnum, and wild rye grass. 

People naturally want to plant things that are special, and special used to be defined by distance--as in exotic plants imported from distant continents. Distance made the botanical heart grow fonder. It's heartening to see a shift in what is viewed as special, towards a valuing of what is truly local.  

The Pleasure and Aesthetics of Native Seed Collection

One of the more pleasurable and aesthetic outdoor experiences in the fall is gathering seeds. I claim no expertise, but adhere to one simple rule: let the stem below the seeds turn brown before harvesting. And harvest when the seeds are dry. Also, be messy. Let some of the seeds fall where they would have fallen if you hadn't come along to take some. Alright, that's three rules. But that last rule is especially enjoyable. How many times in your life have you been told to be messy? 

There are more official rules out there for seed collection, particularly of uncommon species, but nearly all the seeds I collect now are either from my backyard or the Botanical Art Garden, both of which I planted. It's gratifying to see these new populations of local genotypes thriving, and to expand their local presence further. 

The plants I harvest from tend to be generous towards a human tendency to procrastinate. Many species hold on to their seeds for months in the fall and into the winter. But the prettiest time to be picking them is sooner rather than later, as they become increasingly weathered and threadbare as winter progresses.

Harvest of wild senna, seen in the first photo at a lovely stage when the leaves contrast with the dark seed pods, can be postponed considerably, as the pods hold onto the seeds for months.

The bright, fluffy clusters of ironweed seeds are easy to identify on stems that can reach 8 feet.

Rose mallow hibiscus (Hibiscus moscheutos) holds its seeds in convenient cups. Best not to wait too long, because there's a slow attrition to spillage and insects as winter sets in.

As with other sedges, the seed clusters of morning star sedge (Carex grayi) will break apart as fall progresses. Some other local sedges with easily collectible seeds are squarrose sedge and fringed sedge.

The seeds of bottlebrush grass, attractively arranged along the stem, were already starting to fall off when I collected them in late October. Just grab the dried stem between thumb and finger and pull upward to strip the seeds. This is an attractive understory grass. 

The seeds of turtlehead (lower left in the photo) are still ripening, having shown their own form of procrastination, waiting until early fall to bloom.  

Collecting seed has extra meaning and purpose this fall, because many of them will be planted along a wooded slope in Herrontown Woods where a large clone of wisteria had pulled down some of the trees, creating openings where sun can reach the ground. Years of effort, particularly with the consistent, transformative work over the past year or two by volunteer Bill Jemas, has largely snuffed out the daunting wisteria clone that had taken over an acre or two, choking other growth as it steadily expanded along this broad hillside. It even somehow traversed the creek and was headed towards the Botanical Art Garden, adding another layer of urgency to knocking it out. Into the void created by our wisteria removal has come garlic mustard and stiltgrass, but this year we pulled those before they went to seed. 

With much of the slope now bare (the photo shows wisteria to the right, cleared areas to the left), it's time to introduce native plants. We could toss the seeds hither and yon, but I like to give them a better chance by being more deliberate. Deer are an issue, of course, given their appetite for native plants, and my plan is to plant seeds in small circles here and there, creating loci a couple feet wide. I like to scrape a thin layer of dirt away, scatter some seeds, then sprinkle some dirt on top and tamp it down. Then I'll place a 3 foot high plant cage around each circle. Those that grow inside the cage should be protected enough to mature and produce seed that can then scatter beyond the cage on its own in subsequent years. 

It's actually a good way to find out which species the deer leave alone, and which they munch on. We are, in a way, creating "deer feeders" by protecting a few plants inside the cages--plants that each year spread beyond the cages, where the deer can eat them. This approach has been successful at the Barden. Thanks to the town's investment in annual deer culling, many of the plants that sprout beyond the cage survive. 

Of course, all of this thus far is talk. Procrastination is a particularly powerful factor when it comes to getting plants or seeds in the ground. There's so much other work to be done! What's real and lovely, and has actually happened, is the seed collecting. 

Pilewort--A Native Weed With Hidden Flowers and Showy Seeds

Some plants have it all backward. Flowers are supposed to provide the show; the seeds, not so much. 

But with pilewort, its the seeds that catch the eye, clustered in raggedy bunches that look like cotton. 

The plant sets up great expectations as it grows and grows, fleshy like a large thistle, but soft and approachable, 

with a pleasant scent when you crush the leaves. What fabulous flowers will crown all this vertical ambition? 

Something looking like a flower bud appears, but it never generates anything resembling a flower with petals. Pollinators visit nonetheless, even though the flowers look like duds. 

During our monthly nature walk at Herrontown Woods this past Sunday, I was grateful that one of the participants pointed out some other activity around the pilewort flowers. A common local ant species was busy tending to a flock of aphids sucking juice from the stems. The ants harvest the aphids' honeydew. 

Pilewort (good luck with the latin name, Erechtites hieraciifolius) is what I call a native weed. They pop up in large numbers in areas that have been disturbed, rising 8 feet high in what looks like a fleshy forest dusted with snow. 

Maybe the name comes from the piles of seeds it deposits all around. Another common name for it is fireweed, because it sprouts abundantly after a fire has swept through.

You might think this plant a menace that will take over. The nonnative lambsquarters, also an annual, can give this impression too, growing densely and tall the first year after a disturbance. But I've learned not to be concerned over their dominant presence. The first year's show of abundance fades in subsequent years until you can hardly find a one. Other plants move in, and pilewort awaits the next disturbance. 

2024 Update: Low and behold, the pilewort did not gracefully fade away this year. Having allowed it to go to seed last year, we are faced this year with a pilewort riot, requiring a sustained effort to pull it before it goes to seed again. Live and learn.

Obedient Plant: Big Pink in a Season of Yellows

Among sun-loving native flowers of summer, the so-called obedient plant shows up all fresh and fulgent just as the party is starting to wind down. Each year it catches me by surprise with its pink when so many other flowers--sunflowers, cutleaf coneflowers, Silphiums, Heleniums--go with yellow. 

Obedient plant (Physostegia virginiana) is also off my radar because it is risky to plant. Its tubular flowers may obediently remain sideways if you push them, but the plant itself spreads aggressively underground. Not surprisingly, it's in the mint family, known for roots that spread hither and yon.

That's why this gardener on Grover Ave was so smart to plant it between a sidewalk and the road, where its capacity to spread is limited.

A similar strategy to curb its spread was used in front of Jay's Bike Shop. 

Obedient plant also pops up in several spots in Herrontown Woods each summer. Hard to say if it was planted or part of the indigenous flora. Interestingly, it doesn't seem to spread much when in an open woodland rather than a garden. Many other species that seem modest, even rare in the wild--various native sunflowers, groundnut, virgin's bower, fringed loosestrife--also turn rampant when planted in the comparatively tame environs of a garden. 

The Pleasures of American and European Elderberries

One of my favorite shrubs, the elderberry, took on new facets and dimensions this year. 

When I was a kid, we'd drive out to the countryside and harvest its berries, clustered on broad disks. What they lacked in size they made up for in numbers. Brought home in big brown paper grocery bags, they were soon on their way to becoming delicious jelly and pies. We made jelly out of wild grapes, too, but elderberries had a flavor all their own. It took a little time to strip all those small berries off the stalks, but the reward lasted all year.

How we managed to beat the birds to the berries back then is a mystery. Though we grow the shrub in our backyard in Princeton, the catbirds often make quick work of the berries.

Elder Flower Syrup

Fortunately, there's something amazing to be made of the flowers, and this year, we finally made it. One summer many years ago, a friend had served me an elder flower drink that was revelatory, but somehow I got the idea that only the flowers of the European species (Sambucus nigra) could be used. Searching today's internet, that distinction appears to have dissolved. The elderberry native to the eastern U.S., Sambucus canadensis, makes perfectly fine elder flower syrup. 

Our friend Joanna served as mentor and activator, directing us to pick the clusters when all the flowers were open but still fresh. For best flavor, one website suggests picking the flowers in mid to late morning. 

Some Caution

Some recipes are less concerned than others about including any fragments of the green stems, which are toxic. Only the flowers and the cooked ripe berries are edible. We stripped the petals off the stems by hand, which is time consuming but delivers good results. 

Making the Syrup

Recipes vary online, but all use lots of sugar and sliced lemons, which are added to the flowers along with some citric acid. Pour in boiling water and let it sit, covered, for most of a day, then pour through a cloth to get the syrup. We had to call around to supermarkets and hardware stores to track down some citric acid. 

Pour a little of the syrup in chilled water, white wine, or prosecco. It was a big hit at our Veblen Birthday Bash at Herrontown Woods. 

Elderberries Join a New Family

One bit of news from the turbulent, restless world of scientific nomenclature: the elderberry has been uprooted from its long-running membership in the Caprifoliaceae family and now rubs phylogenetic branches with Viburnums and a couple other genera in the Moschatel family, also known as the Adoxaceae. 

A Curious Variety of European Elderberry

On a recent roadtrip, I encountered a strange, purple shrub in a couple gardens. I was surprised that the botanist I now carry in my pocket, better known as an app called Seek, was calling it an elderberry. "Black tower" elderberry, perhaps--one of many bred varieties of the European elderberry. It's pretty, and different, but it's not something I personally would plant. Each gardener evolves differently, but for me, the sequence of interest across fifty years went from vegetables, to roadside weeds, to pretty ornamentals that were native or not (a black tower elderberry would be in this category), then to the community of native species that coevolved together over ions. It's a fidelity deeply rooted in a sense of place. 

Johnny Elderflower Strikes Again

If some combination of the abundant flowers and berries breeds in you a love of native elderberries, you can easily go forth and propagate them using 2' long cuttings from the dormant stems. The bushes are typically found in wet, edge habitat where there's some sun. Hopefully you'll emerge from your winter dormancy before the elderberry bushes, because they leaf out earlier than other native shrubs. Press the bottom end of the "live stake" as deeply as possible into soil to make roots, leaving a few buds above ground to make leaves. I've used this highly economical approach to propagation in many places over the years, most recently in a wet, open woodland area at Herrontown Woods. The act of planting is deliciously lazy, but followup is needed in the form of watering during droughts the first summer, and protecting them from deer browsing with wire cages. If things go well, in a few years the special flavors of elderberry will be all the easier to be had in Princeton.

Harrison Street Park: Contrasting Tales of Trees and Wildflowers

Most people drive by Harrison Street Park unawares. It's an old neighborhood park that lacks parking, and so mostly serves those who live close enough to walk there. Whenever I think to stop by this surprisingly spacious park close to Nassau Street, it's to check in on dreams living and remembered. 

One dream is bringing back the American chestnut. We've planted a number of chestnuts around town that are 15/16th native. They were originally crossed with a resistant asian chestnut, then backcrossed with the aim of ending up with a predominantly native chestnut tree that still carries the Asian species' resistance to chestnut blight. Some of these trees have proven susceptible to the blight, but two in particular have resisted the blight thus far. One of these is in Harrison Street Park, nearly 20 feet tall now. 

We also planted two native butternuts there, another native tree that has been marginalized by an introduced disease. It's good to see them thriving and starting to bear nuts. 

There's also an attempt by the town, successful thus far, to keep a grove of ash trees protected from the introduced Emerald Ash Borer, via systemic applications of insecticide. Another small grove of trees was planted through a citizen donation and collaboration with the Shade Tree Commission.

Other dreams for Harrison Street Park, involving wildflower plantings, have not done so well. Princeton Borough had great dreams for this park at one time. In 2006, they hired me to conduct an ecological assessment and write a stewardship plan. Then they hired a landscape architecture firm from Philadelphia to design improvements to the park. Neighbors offered many ideas and expressed many opinions. The old wading pool--a relic from a distant, more sustainable era when kids gathered in their neighborhood parks in the summer--was removed, the play equipment was updated, and a few new features were installed. 

Some $30,000 was spent on new native plantings that looked good for a year or two before going into steady decline. The idea was that neighbors would care for all these new plants. Of course, a drought promptly ensued. Some of the neighbors rose to the occasion to keep the plants going, but the extensive flower beds required more than an initial season of zeal. Neither the borough maintenance crews nor any of the neighbors had the training or interest to keep the flower beds weeded over the longterm. 

This flower bed is now a massive stand of Canada thistle and mugwort. 

The plant with the big leaves is a common weed in the midwest that is showing up more and more in Princeton. It looks like rhubarb, but is in fact burdock. 

There's a swale in the park that receives runoff from a private parking lot next door. These wet, sunny spots can tip the balance towards native species. A friend and I planted various floodplain species--joe pye weed, tall meadowrue, etc--but also planted Jerusalem artichoke, which is a native sunflower species with edible tubers. 

When planting an aggressive plant like a native sunflower, it's easy to believe one will follow up and keep its expansionist growth in check. That's almost never the case. The sunflowers has spread aggressively underground over the years, and have long since swallowed the other wildflowers in their dense growth. Each year the sunflower clone expands, as park crews mow around its fringe. 

We also planted a couple pawpaw trees there, but they were overwhelmed by the sunflowers. A couple black walnut trees sprouted on their own and had much better luck, somehow managing to rise above the sunflowers. Trees that plant themselves tend to be more successful than trees planted by people. On the upside, the sunflowers are so aggressive that they require no weeding, and there's a dazzling display of yellow in the fall. But, like some of the other plantings at Harrison St Park over the years, it's not what was originally envisioned. 

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.