 Instead, they form colonies which spread by vegetative reproduction along rootstocks.A colony of "G. brachycera" at Losh Run, Pennsylvania was found to be long when surveyed.If this colony grew clonally from a seed deposited along the Juniata River at the rate of per year, it would be about 13,000 years old, the oldest living organism in the United States and second oldest in the world, eclipsed only by "Lomatia tasmanica".