Continent with other islands in the Pacific into one continent called Oceania. This divides the entire land surface of Earth into continents or quasi-continents. The ideal criterion that each continent is a discrete landmass is commonly relaxed due to historical conventions. Of the seven most globally recognized continents, only Antarctica and Australia are completely separated from other continents by the ocean. Several continents are defined not as absolutely distinct bodies but as ""more or less" discrete masses of land". Asia and Africa are joined by the Isthmus of Suez, and North and South America by the Isthmus of Panama. In both
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