The problem with problems is, if they are solved early on, no one knows how big a problem they could have ultimately become.
-- Yurs Trulee
Many of us are immigrants in our own country. If, for example, you moved to the east coast after growing up in the midwest, or vice versa, you're an immigrant of sorts, bringing experiences and sensibilities that may be new to others around you. My multiple immigrations in my home country have a botanical component. As I've moved from the midwest to the south, then to the east coast--tending to habitat wherever I live--I've brought with me experiences that less traveled land managers may not have had. And like an immigrant from another country, I don't lose a caring for my land of origin.
It's interesting to see how this plays out with invasive species. If I see a species like Chinese bushclover, which grows rampant in North Carolina, starting to pop up in fields in Princeton, I can warn others of the risks of not taking action. Similarly, when I spotted garlic mustard and lesser celandine growing in Durham, NC, I sounded the warning, having seen how the plant has behaved in northern states. And if I hear that the stiltgrass that chokes many woodlands here in the east is starting to spread to my home states of Wisconsin and Michigan, I can do my best to send warning back home to act early and often. Otherwise, each state has to learn lessons the hard way.
At the same time, one hesitates to raise alarm. Might a plant that's invasive in one state prove more docile in another, due to differences in soils and climate? This quandary played out recently while driving to a band rehearsal on Lawrence Station Road, down past Quaker Bridge Mall. Growing along the roadside amidst autumn's reds and yellows was a sudden burst of white. Having lived in the piedmont of Durham, NC, I could see both the beauty and the portent of this unusual presence in the local landscape.
Groundsel Tree is deceptive in many ways. It's called a tree, but grows more like a big multi-stemmed bush. The bright clouds of white produced in late fall look like flowers, but are actually thousands of fluffy seeds that fly far on the wind.
Another deceptive trait is that groundsel tree (Baccharis halimifolia) is native to the New Jersey coast. Perhaps we should celebrate that this coastal species has moved inland bringing its fall nectar and showy seeds to the Princeton area.
And yet, my years in Durham, NC showed me how aggressive this coastal native can become when it spreads along freeway corridors up into the inland piedmont. It can invade grasslands and create dense, exclusionary stands (see photo), reminiscent of the callery pear that lines many roadsides in New Jersey.
But is it behaving that way in NJ? I sent an inquiry to the Stewardship Roundtable listserve that many of us land managers participate in. Responses mixed praise for its positive qualities with some mild concerns. The specimen I encountered on Lawrence Station Road looked to have sprouted only two progeny since my first encounter with it, ten years ago.
One respondent, David Seiler, mentioned a big patch growing along 295 past 206. That sounded more like the behavior I had witness in NC.
I decided to check out the big patch along 295, now being a good time to spot it, while it is bright white with seed.
Hard to miss the long stretch of that bright white, mixed with the tassels of Phragmitis. But the backdrop of evergreen trees isn't natural to our area either, suggesting the groundsel trees were part of an ornamental planting installed between the freeway and a housing development. A well-intentioned planting could provide abundant seed for a new invasive in Mercer County.
Another data point on the iNaturalist map took me to a beautiful pond on the backside of the fabled Lawrenceville School that has a beautiful stand of bald cypress.
Where the groundsel tree is documented on iNaturalist, I found stumps. According to staff at the school, a landscape architect named Elaine Mills marked plants for removal along the pond this fall. If the stumps are former groundsel trees, were they removed for aesthetic reasons or over concerns of potential invasiveness? No answer yet.
So, this is the quandary. As a land manager, do you sit back and let a newly arrived species like groundsel tree grow, appreciating its positive traits? Or does one heed warnings of its potential invasiveness in other states, and remove it while control is still possible?
The problem with problems is, if they are solved early on, no one knows how big a problem they could have ultimately become.
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