Walden

On average, common species are flowering seven days earlier than they did in Thoreau’s day...[Researchers have] determined that 27 percent of the species documented by Thoreau have vanished from Concord and 36 percent are present in such small numbers that they probably will not survive for long.

“It’s targeting certain branches in the tree of life...They happen to be our most charismatic species — orchids, mints, gentians, lilies, iris.”

-- from Thoreau Is Rediscovered as a Climatologist