Monday, May 28, 2018

Unexpected Spring Sightings

I used to take care of indoor plants, among them being Dracaenas like this corn plant, but had never seen one bloom before. This one was at the West Windsor Senior Center, where our McCarter Onstage community theater group performed recently.

Meanwhile, about a week ago, my daughter called me to her bedroom with a tone of urgency, and showed me a large wasp that had somehow found its way inside and onto a bookshelf. It was big--big enough to be a cicada killer, which is of very little threat to people and seeming early on the scene if it wants to go after cicadas. I got it to climb onto an object, took it to an open window, and blew it off into the great outdoors. Time to get those screens out of the basement and onto the windows.

Galls always come as a surprise, no matter how common. This one's looking like a hickory leaf gall, on a hickory sapling at the "Phoenix Garden"--a native garden we're planting at Herrontown Woods where a pine grove was progressively knocked down by wind and ice storms in recent years. Supposedly an insect dwells inside these galls, but none could be found.

Tulip tree (a native relative of magnolias known as Liriodendron tulipifera) bear flowers high up in the canopy. Only the occasional fallen twig reveals what complex beauty lies overhead.

Tuesday, May 22, 2018

A Sampling of May Flowers

No theme here, just flowers. Red buckeye, for instance, though this one doesn't look very red, a small tree planted occasionally along streets--this one under powerlines where it's small size should prevent it from tangling with the lines in years to come. It's native, though the only time I saw it growing in the wild was in the coastal plains of North Carolina.

Adding to the red end of the spectrum is a Rhododendron at Veblen House. We recently moved a carefully excised portion of the last known and deeply shaded native Rhododendron in Herrontown Woods--an azalea species--to the botanical garden next to the HW parking lot, to see if it might grow, thrive and bloom once again, if given some light and tlc. Native azaleas are said to have been a common sight in the past along the edge of Herrontown Road.

Princess trees are an introduced species often found along interstates. There are several growing at Herrontown Woods that we're leaving to grow for now. They bloom before leafing out.

The Japanese and Chinese wisterias also bloom before leafing out, making for a striking display if contained. If not contained, they become a menace, spreading into woodlands where they smother and weaken trees, and so dominate that nothing else can grow. Fortunately, they don't seem to spread by seed. Otherwise, Princeton would have long since been engulfed. There is a native species of wisteria that grows in the southeastern U.S.. It blooms when the leaves are already developing so is less spectacular. It is less aggressive, but even so must be planted with caution. Other native vines like virgins bower, groundnut, and Virginia creeper may not dominate in the wild, but can be surprisingly aggressive in the less competitive environment of a garden.

Fringe tree is a lovely native shrub, rarely seen in the wild. My one encounter was on some land we preserved in Durham, North Carolina. This fine specimen grows in a carefully tended garden at Franklin and Snowden in Princeton.

A less tended example is in Community Park near 206.

More common than fringe tree are native black locust and black cherry, both of which have white flowers around now. Black locust's flowers are usually high up, but this specimen along Herrontown Rd were low enough to photo. The tree has yellow, rot-resistant wood useful for fenceposts and burns clean and hot in the wood stove. Towering specimens grow near historic houses in the area, which doesn't seem a coincidence.

More whiteness comes from Deutsia, a well-contained shrub sometimes planted as a low hedge. Not native, but doesn't seem to spread into wild areas, or even in the yard.

Everyone knows flowering dogwood, made bright and beautiful by its bracts.

Sad to see many older flowering dogwoods in my neighborhood dying back and ending up as dead wood piled in the street. The loss, either to old age or to an introduced fungus that causes anthracnose, heightens the appreciation of those that survive.

Far more rare and less known than the flowering dogwood is the alternative-leaved dogwood, only two specimens of which I have encountered growing in the wilds of Princeton, at Herrontown Woods.

Wednesday, May 09, 2018

Nature Walk at Herrontown Woods, May 12, 2pm

Update: Nature walk is on, though may be shorter due to potential rain later in afternoon. Be ready for some mud here and there.

On Saturday, May 12 at 2pm, the Friends of Herrontown Woods (FOHW) will host a nature walk at Herrontown Woods in Princeton. The walk will include a brief introduction to the native botanical garden being created at Herrontown Woods by FOHW volunteers, a walk up through the boulder fields of the Princeton Ridge, and end with refreshments.  Showy orchid and other rarely seen wildflowers of the Princeton ridge are coming into full bloom.

The walk will be co-led by botanists John Clark and Steve Hiltner. John L. Clark teaches at the Lawrenceville School, and recently gave a talk at DR Greenway about discovering new species in Equador. Steve Hiltner is a naturalist who writes about nature at, and is president of FOHW. 

Meet at the Herrontown Woods parking lot, off of Snowden Lane, opposite Smoyer Park.

Friday, May 04, 2018

A World Paved With Fig Buttercup?

There are many types and degrees of invasive behavior in plants. Dandelions are weedy in lawns but cannot survive in the shade of a forest. Japanese maple and Rose of Sharon may seed prolifically in a garden, but rarely show up in the nearby nature preserve. Bamboo, kudzu and Asian wisteria become like castles in the landscape--formidable, exclusionary, and deeply entrenched but limited in extent. They form dramatic, isolated clones that fortunately leave most of the forest untouched. Stiltgrass by contrast is a frail annual easily pulled, which nonetheless can have a far greater impact, coating the ground of large swaths of forest with billions of plants. It thrives in shade but tolerates sun, spreading into garden beds and lawns.

We, with our big brains and bodies, are built to take on large, distinct foes, yet quickly grow discouraged when faced with a threat that is small but hugely numerous, whether it be an overabundance of carbon dioxide in the atmosphere, plastic in the ocean, those tiny odorous house ants in the kitchen, or a ubiquitous weed in the garden. That pile of papers on the desk falls into this category as well. If the small, numerous thing is a disease pathogen that attacks us directly, we have strong institutions that engage to defend us. But if the small, transformative force represents an indirect threat, impacting our environment--our oceans, landscape or climate--rather than us directly, we lack both sufficient institutions and the will to resist. This can be considered society's achilles heel.

As a local example, our big-little hamlet of Princeton is being gradually paved over by a little plant that is pretty, and seemingly benign, yet is also extraordinarily aggressive, poisonous to wildlife, and overwhelming in its numbers and rate of spread. By mid-summer, it will have faded back into the ground, but in spring it looks like an expanding rash coating the land. It numbers in the billions, and cannot be easily pulled. Even its common name is hard to get a good hold on, with "fig buttercup" having displaced "lesser celandine" because the plant has the buttercup flower and fig-shaped tubers. The scientific name is Ficaria verna, with verna referring to its spring growing habit.

In the photo is an advanced invasion in Pettoranello Gardens that long ago spread downstream to Mountain Lakes Preserve. The more land it covers, the less edible the landscape is for wildlife. Our investment in open space acquisition is undermined as the acreage of functional wildlife habitat continues to shrink due to displacement of natives by introduced species that wildlife won't eat.

Now the fig buttercup is spilling into the nearby neighborhood along Mountain Avenue, spreading down-slope from one yard into the next. This patch spread through the fence, and through the neighbor's yard,

then popped out under the fence on the other side, ready to head further down the street. This species behaves like plastics pollution in that it becomes widely spread for lack of any organism able to eat it. Nature's checks and balances, developed through eons of co-evolution and adaptation, are circumvented when a new species like fig buttercup is introduced from another continent.

Here it is at Elm Court, a few blocks further on, poised to spread into and eventually coat their detention basin.

There used to be some solace in thinking that fig buttercup was limited to low, wet ground, but here it has become established along a slope next to the stage at Pettoranello Gardens. Audience members will slip on it, pick up some of the underground bulbs in the treads of their shoes, and transport the plant to new locales. What will stop it from eventually paving all of Princeton?

For contrast, here is the native marsh marigold, with which the fig buttercup is often confused. It's growing on the edge of the stream in Pettoranello Gardens because I planted it there a few years back. It's bigger and more showy, but doesn't take over like the fig buttercup. This is the classic example of how many landscapes have become dominated by invasive introduced species, while the native plants become rare.

Another attractive native yellow flower in spring is celandine poppy (unrelated to "lesser celandine"). I've never seen it growing naturally in the Princeton area, but it is used in landscaping. It has a nonnative lookalike that can be weedy but not as invasive as stiltgrass or fig buttercup.

Because fig buttercup is so aggressive and so hard to remove manually, careful use of herbicide is really the only means homeowners and preserve managers have to prevent it from getting established and ultimately taking over. Early detection and rapid response are the best recipe for minimizing herbicide use. We can't wait a million years for nature to adapt and re-establish balance, as one of the more bizarre books on invasive species has claimed.

Maybe research could eventually lead to a biological control being introduced to limit the fig buttercup's aggressive spread, but that requires that institutions be in place that can afford to do the many years of research and testing required, with no guarantee of success. In the meantime, fig buttercup continues to pave Princeton, one nature preserve and yard at a time.

Goose Family Moves In

"Beware of the goose family," says an improvised sign at the entry to a local medical facility off of Harrison Street. "STOP! Authorized Personnel Only," the red stop sign declares, though it might more appropriately say "Unauthorized geese only."

Flattering, I guess, to have a goose family set up shop in this unlikely habitat, next to a busy building, like a mobile zoo that makes office calls. Maybe they feel safer on the elevated ground, or feel at home under the foundation planting of native arrowwood. Every goose knows that Viburnum dentatum is one of the more attractive shrubs growing in floodplains.

That's the female sitting on her nest in the foreground, with the male standing guard some distance back.

The warning signs probably went up after a passerby reportedly came too close and got knocked to the ground by a bop on the head, curtesy of the protective male. The geese, I hear, used to nest down along the nearby stream, but if our experience with chickens in the not so distant past is any indication, the predators have upped their game and may pose a threat even to the formidable goose.

I was impressed that the Goose Family in Residence program is being allowed to continue, and suggested they install a 24/7 Goosecam to broadcast on the internet. Not sure what the bucket is for: donations for the ducklings?