You'll likely recognize this species of tree, with the pretty, fuzzy red flowers, of which there are apparently almost 5,000 across the city. It's called a New Zealand Christmas tree, or Metrosideros excelsus, and despite being widely planted in the 1980s and endorsed by the City, it's now been recognized as a mistake and a bit of a nuisance species. This is because its roots -- which can grow to 9 inches in diameter -- can destroy infrastructure like sewer pipes and sidewalks once the tree reaches maturity, which these trees are doing by the thousands right about now here in S.F.

Still, homeowners face a battle from advocates like the Department of Urban Forestry who, despite acknowledging that the tree was a mistake and shouldn't be planted anymore, still defend the presence of mature trees in general and are basically telling property owners to suck it up.