RANCHO MIRAGE, Calif. -

To most, the brown leaves on pepper trees means dead leaves,  nothing unusual. Turns out it's more than that, which is also nothing unusual.

"It's common in pepper trees. As they fail, most people aren't replacing pepper trees with pepper trees,” Robert Downing, the landscape supervisor at Vintage Nursery, said. 

Downing told us the jelly-like balls on the trunk are conks, a fungus inside the tree killing it.  They are not harmful to people. 

"Rotting from the inside out. They look healthy from the outside, because what's happening is happening on the inside. But eventually the tree can't support itself and it fails,” Downing said. 

We tried to talk to people who own these trees, but could only find them on public streets, like Dinah Shore in Rancho Mirage. 

"It's the real lazy, willowy looking tree that used to be real common out here but is becoming less common because of this problem,” Downing said. "Real common in California peppers is they get planted too deep. That will cause root rot. It'll start that way. Mostly poor pruning and planting too deep are the causes."

Downing said the trees will eventually rot from the inside out, and fall apart from wind. 

"The damage is done, especially by the time you see conks the damage is done. It's irreversible," Downing said.