The gash to the silver linden tree in Evans Way Park in the Fenway neighborhood was so fresh, so raw that sawdust still sat sprinkled at the base of the trunk.
The 60-foot-tall linden had been the victim of a nighttime mugging.
Clandestine vandals armed with chain saws and hand saws have recently been gouging burls from trees in Franklin Park, the Riverway, and the Jamaicaway, in what could signal a burgeoning underground market for the valuable trunk knots.
Greg Mosman, the city of Boston’s arborist, noticed burls were disappearing from trees during routine inspections at Franklin Park this past spring.
“And I didn’t think too much of it,” Mosman said. “But then I started to notice some on the Riverway that were missing.”
Soon after, Mosman received a call from Brookline’s arborist asking whether he had noticed missing burls.
“They had a similar thing going on, to the point that they noticed climbing lines and a manual hand saw left behind,” Mosman recalled. “The ones I’ve noticed here [in Boston] are done with a chainsaw, which is pretty crazy because you’d think someone would’ve noticed.”
Burls are round trunk bulges that appear when a tree is injured or diseased. They are rare and highly prized by furniture makers, wood turners, and artists for their intricate grain patterns and figure, said John Nitzsche, a member of the Eastern Massachusetts Guild of Woodworkers.
Most commonly, they are used to make decorative bowls, often displayed in galleries and museums, that can retail for $500 to $1,500, said Dave Eaton, president of Central New England Woodturners, a 100-member club.
“The exceptional quality of a particular burl is unknown until you actually cut into it. Most of them are trash,” Eaton said. “However, there are a particular number of the burls that are exceptional.
“The decorative quality of burl is very, very high,” he said. “A single individual bowl itself is unique.”
Although vandalizing trees for burls is not common, some in the wood industry are sufficiently aware of it that they have given it a name, Eaton said: drive-by de-burling. “It’s terrible and unnecessary,” Eaton said. He said he doubts the vandals are woodturners. “We have very high regard for trees.”
The damage to a tree is more than skin deep. It can shorten its lifespan.
Depending on the size and type of a burl, a seller could get $50 to $500 per piece, Eaton said. That could translate into quick cash for a vandal who knows where to sell the amputated slab of wood.
Mosman said he has no idea who could be targeting the city’s trees, but suspects they are striking at night.
“I don’t know if it’s a woodworker doing it for themselves, or somebody selling these to a woodworker,” Mosman said. “I’m honestly baffled.”
Mosman said burls have also gone missing from trees in Watertown’s Arsenal Park.
At Franklin Park, where most of the damage in Boston has happened, vandals plunge deep into the woods to do their deed, picking spots that don’t often see human activity. Anyone caught removing wood from the park could face serious charges because it is considered a quarantine zone by the US Department of Agriculture because of Asian longhorned beetle sightings, Mosman said.
The dismemberment of the silver linden, growing in Evans Way Park for more than 50 years, likely took about two minutes with a chain saw, given the smooth markings along the severed area, said Mosman, who discovered the damage Tuesday. The deed was pretty brazen, he said, because the tree is about 15 feet from a parking meter, in an area crowded with students and tourists.
“I’ve never seen this before, and I’ve been doing this job for 10 years,” Mosman said. “This is the closest to the street that I’ve seen [a burl removed].”
Mosman has seen similar damage along the Riverway and Jamaicaway, which are controlled by the state’s Department of Conservation and Recreation. An agency spokeswoman said field staff have no knowledge of the vandalism but “will certainly now start looking for it.”
Mosman said he has reached out to different groups to raise awareness, and urges the public to contact police if they see someone cutting into trees after business hours or if there is no evidence the work is being done by a government agency.
“It’s definitely vandalism,” he said. “It’s not the worst thing you can do to a tree, but it’s up there.”Katheleen Conti can be reached at email@example.com. Follow her on Twitter @GlobeKConti.