Boole (tree) the largest in Converse Basin Grove, was named around 1895 by A.H. Sweeny, a Fresno doctor, after Franklin A. Boole, a supervisor of the logging operation who spared the tree's life due to its great size. Before 1931, it was thought by many to be the largest tree in the world (although the General Grant Tree was more popularly known as the largest tree in the world at that time), but it is now known as the sixth largest tree, after five other giant sequoias: the General Sherman tree, the General Grant, the President tree, the Lincoln tree, and the
Largest organisms over . The largest organism in the world, according to mass, is the aspen tree whose colonies of clones can grow up to five miles long. The largest such colony is Pando, in the Fishlake National Forest in Utah. Another form of flowering plant that rivals Pando as the largest organism on earth in breadth, if not mass, is the giant marine plant, "Posidonia oceanica", discovered in the Mediterranean near the Balearic Islands, Spain. Its length is about . It may also be the oldest living organism in the world, with an estimated age of 100,000 years. Green algae are