This branch-based battle started earlier this year when the Passyunk Square Civic Association took down the names of neighbors who wanted a tree. They were free, thanks to an $8 million program that aims to combine state money and private dollars to plant 20,000 trees in the region through fall 2007.

Joe Kelly and Pat Ryan, who live across from Columbus Park at the corner of 13th and Wharton streets, signed up because they like the shade and beauty trees offer. Looking down 13th Street, trees are conspicuously absent from the sidewalk in front of homes belonging to lifelong Italian residents and their relatives. During the 15 years Kelly and Ryan have lived here, old-timers have told them trees are dirty and attract unwanted birds.

"If there's a new tree," Kelly says, "you can assume it [was planted by] a new person."

SEEDS OF DISCONTENT: This young serviceberry tree is pitting South Philly old-timer against newcomer. : Michael T. Regan

Since the tree would be planted in front of their house only, they figured no one would make much of a fuss. They were wrong.

Thomas Rumbaugh, who lives three doors down, had a problem with it.

When a contractor hired by the civic association came around in March to cut up the sidewalk in preparation for the 105 trees requested by homeowners, he mistakenly cut two tree pits in front of Kelly and Ryan's place: one close to the stop sign and one about eight feet away. So Rumbaugh went to state Rep. William Keller's office, where he's a regular, to call the Fairmount Park Commission, which approves the sites, and the Streets Department, which says a tree cannot be planted within 75 feet of an intersection.

"It's just an accident waiting to happen in a neighborhood where children are concerned," Rumbaugh says, referring to the nearby Christopher Columbus Charter School.

They told him they'd investigate.

The morning of the tree delivery, Rumbaugh approached Sarah Waters, who volunteered to coordinate the tree distribution.

"Do you work for the Fairmount Park Commission?" asked Rumbaugh, who wears his gray hair slicked straight back and parks his white car in front of a fire hydrant.

"No," she responded.

He then left, only to return later that morning and ask, "Are you in charge of the trees?"

She told him the second pit was cut by mistake, but a tree was assigned to the first pit dug further from the stop sign.

"He obviously just didn't want the tree there," says Waters, "but he indicated he was in charge and somehow connected in the city and a tree would not be placed there."

Since Ryan and Kelly weren't home, she temporarily sent the tree to a neighbor's house. Two weeks later, Ryan and Kelly waited until a Sunday morning when they figured Rumbaugh was at church, planted the tree themselves and waited to hear the city's ruling.

"Our position is if the tree comes out, we sue," says Ryan. "And if our tree comes out, so do all the others." If the city upheld the Streets Department's intersection rule, practically every tree in the neighborhood would have to be ripped out.

While the battle started over a tree, it epitomizes the effect shifting demographics is having on the community.

"We represent a new mind-set," says Kelly, whose mom appreciated nature so much that she had fallen leaves from New England trees shipped to their Florida home. "Even though we've lived here all these years, we had never really taken a mind-set in line with the newcomers."

Until now.

What the lifers don't realize, he says, is that "along with these tree huggers have come increased property values." (Kelly and Ryan bought their place for $25,000; homes around them are now selling for $300,000.) People like Ryan and Kelly have been integrating into South Philly for years, but lately a steady stream of young families and couples have bought houses, renovated them and joined the civic association as a way to have a stake in what happens there. But lifers like their immediate neighbor, a barber named John, aren't too excited about higher property values, which just translate into bigger tax bills anyway. He runs the barbershop his father started in 1932. Today, he offers $8 shaves.

Five years ago, John watched his neighbors replace an old bocce court shelter with a dog run. The tree represents a similar affront.

While he complains that his customers could get their shoes stuck in the mud around the tree and car doors could knock into it, he has nothing against greenery. He even planned to plant vinca and New Guinea impatien flowers in Margate over the weekend. He just would have liked the courtesy of a heads-up.

"If I was going to plant a tree," he says, "I would go to the neighbors and say, 'Look, we're thinking of planting a tree. What's your feelings?'"

Mindy Maslin, who runs the Pennsylvania Horticultural Society's Tree Tenders program, has encountered similar resistance in Fairmount, some pockets in West Philly and wherever older residents mix with new ones. Maslin tells them trees clean the air, reduce storm water runoff and temperatures, elevate moods, increase a sense of safety and slow traffic. Her program teaches volunteers how to properly plant and care for trees and refute complaints that trees bring rats, are dirty, attract birds, break up the sidewalk and tangle power lines.

Mike Hardy of UCGreen, a West Philly planting group, says people must be willing to change. "I think you have to weigh the benefits as opposed to, 'I don't want birds crapping on my car,'" he says.

Community groups work with the city to plant so that the vocal anti-tree minority has no choice but to tolerate their neighbors' trees. New urban dwellers "have cracked the mold of this previous tyranny against trees," Hardy says. For example, the Passyunk Square Civic Association noticed people were vandalizing trees around Capitolo Park. On May 5, they dedicated the trees to the city's living police officers, giving the force much-needed thanks and ensuring the trees' protection. Planting organizer Geoff DiMasi sees it's working. While he was pruning, a cop stopped him and asked, "Can I see your Tree Tender card?"

As for Ryan and Kelly's tree, neighbors agree that the Streets Department and park commission, which did not reply to repeated requests for comment, need to coordinate their guidelines to reflect the reality of where trees are planted.

For now, the park commission has ruled that the tree stays. And tree proponents have showed Rumbaugh they have the right to a greener neighborhood.

Rumbaugh says he's done fighting.

After all, it's just a tree.