Tuesday, April 4, 2017

Lesser Celandine: A botanical disaster

Acres and acres of rich floodplain forest are blanketed with dense mats of a highly invasive Eurasian plant, the Lesser Celandine, Ficaria verna, at Whetstone Park in Columbus, Ohio.

On a trip to Indiana last week, I found myself headed west on I-70 - the only pragmatic route for travel to Indianapolis and vicinity from here. As I passed by the Great Miami and Stillwater rivers near Dayton, I noticed great green and gold carpets cloaking the floodplain forests. The dreaded "strangler buttercup", or Lesser Celandine!

This thoroughly noxious plant has really been picking up steam in recent years. It's been a localized scourge in some areas for a long while, but now is steamrolling through floodplain forests at an epic clip. After witnessing the Dayton-area infestations from my 75 mph drive-by, I resolved to visit Whetstone Park near my home after I returned.

I hadn't been to Whetstone in early spring for a number of years, but even then large patches of celandine were already established. What I saw on my visit yesterday stunned me. It was a botanical Armageddon. Long before I even got to the lower reaches of the park and the floodplain of the Olentangy River, I began to see large patches of the stuff in the park's lawns. The floodplain was especially depressing, and the photo above sums up the situation well. The overwhelming majority of native flora and fauna have been totally displaced by the botanical scourge that is Lesser Celandine. Only the overstory trees remain native, but even they are threatened by large clinging draping masses of the invasive Winter-creeper, Euonymus fortunei. The understory is thick in many areas, but shrubs are now nearly completely comprised of another  highly invasive species, Amur Honeysuckle, Lonicera maackii.

We have the nursery industry to thank for Lesser Celandine, which, amazingly, is still readily available in the trade. Just google "lesser celandine nursery" and you will see. A popular cultivar is the aptly named "Brazen Hussy".

It's not hard to see why this plant would be a hit. It is showy, and a highly successful groundcover. Probably, when this thing first made its way to our shores and into the nursery trade, no one really knew it would eventually vault over the garden fence and create ecological chaos with native habitats.

But by now, we should be learning some lessons about the likelihood of invasiveness among introduced plants. If it is an extremely rapid to spread groundcover that grows readily from detached vegetative  parts such as tubers and bulblets (such as celandine), we're probably in for trouble. If it is a woody plant - tree or shrub - that has colorful berries and co-evolution with birds as vectors to distribute those fruit, we're probably in for trouble. Further, if the introduced plants hail from Eurasian habitats and climates similar to ours, we're probably in for trouble.

A sad pair of native Virginia Bluebells, Mertensia virginica, attempt to punch through the dense mat of celandine. The loss of native wildflowers and other native species due to this horrific infestation is stunning. Where once thick stands of bluebells, trout lilies, various native buttercups, sedges and much more flourished, now there is little to nothing other than the overwhelming Eurasian botanical armies. Attendant with the loss of the native flora is a crash in native pollinating insect populations, and many other forms of animal life.

When a celandine infestation reaches the epic proportions of the invasion depicted here, I'm not sure what can be done. Abetting this plant's rapid spread is that it best grows on regularly flooded river terraces, and the floodwaters quickly sweep plant parts into new terrain. I suspect that eradication of a given population, such as at Whetstone Park, is a long labor-intensive task, and one that would require many years of follow-up. Not to mention long-term diligence, as plants will constantly be reintroduced to the site.

The degradation of our habitats by the onslaught of nonnative invasive plants is depressing indeed.

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2 comments:

Lori said...

Thanks for educating your readers on this. Never heard of it and didn't know this. I'm really trying to plant just native plants in my yard. Frankly, they just really DO better.

Judy Ganance said...

Very much appreciate your coverage of this tragedy. Very much parallels the death of the coral reefs. I am horrified this and euonymus and English ivy are stil in the nursery trade. I am vigilant, armed with glyphosate, in killing off any that appears in our yards and back forest. Your article was so well written I will share with neighbors whose garden beds are becoming victim to this "brazen hussy"!