15 September 2015
Here’s a plant that’s easy to find in Maine but is nearly gone from Pennsylvania even though our state is in the middle of its range.
Hobblebush (Viburnum lantanoides) is a shrub 6-12 feet high that grows in rich moist forests from Quebec to Georgia. Its arching branches hold pairs of leaves with delicate white flowers in the spring (click here to see) and abundant fruit in the fall that ripens from red to blue. It’s called “hobble” bush because its long branches take root where the tips touch the ground, then hobble passersby.
Hobblebush is not extinct in Pennsylvania but it’s extremely hard to find and is extirpated from most counties. In 20 years of Pennsylvania hiking I have seen it only once, growing on top of an isolated, sheer-sided, 15-foot high boulder near Cook Forest.
For plants, habitat loss is the usual cause of local extinction but hobblebush disappeared from Pennsylvania without the help of bulldozers. The agent of change here is white-tailed deer.
Hobblebush is such a favorite deer food that the plant’s abundance is in inverse proportion to the deer population. Where deer are in balance with their habitat, hobblebush thrives and they enjoy its flavor, but in Pennsylvania we have 30 deer per square mile (sometimes 70!) so our hobblebush was eaten to the ground long ago.
This situation is not new. For more than half a century deer have been so abundant in Pennsylvania that they’re forced to consume everything edible from the ground to as high as they can reach. Our forests have browse lines — shown below — and deer eat the hemlocks that shelter them in winter, a case of eating themselves out of house and home. (Click here to read more.)
So that’s why seeing hobblebush in Maine is such a treat and why it’s found on top of high isolated boulders in Pennsylvania. At that elevated location the deer can’t reach it.
Have you seen hobblebush in Pennsylvania? Or is it extirpated from your area?
(photo of hobblebush at Acadia National Park and a browse line in Pennsylvania by Kate St. John,
photo of deer by Steve Gosser)