Virginia round-leaf birch (Betula uber)
Found only in — you guessed it — Virginia, this critically endangered tree was believed previously to be extinct. However, according to IUCN, it was rediscovered along Cressy Creek in 1975 and is now "found in highly disturbed second-growth forest" along a tiny stretch of the river in Smyth County. Only about 11 individual trees remain.
Virginia round-leaf birch trees have dark green leaves (this photo was taken in autumn) and produce catkins up to 2.5 inches long. Though the trunks are slim, they can grow up to 60 feet tall, according to Virginia Tech's Department of Forest Research and Environmental Conservation.