Glacial erratics, invasive species, and other erratic and invasive things.
Erratic at Weeksville, Brooklyn
Stand of ailanthus and other volunteers in Crown Heights, Brooklyn
Balancing Rock, Garden of the Gods, Colorado (W. G. Chamberlain, c. 1900)
(source)
ailanthus sprouts
No. 14. Perched rock, Rocker Creek, Arizona, (William Bell, 1871-3)
