Nothofagus, often referred to as southern beeches, is a genus consisting of 35 species of shrubs and trees. They are native to the tropical southern hemisphere, though fossils of some species were found in Antarctica. The leaves of this genus are sometimes toothed and either evergreen or deciduous. As of 2010, many of the living trees in this genus are very old, and it is speculated that some species are unable to reproduce under their current conditions. The plants produce nuts that are very small and almost flat.
One species in this genus, commonly called red beech or Nothofagus fusca, is the largest beech tree in New Zealand. On average, the tree is 80 to 100 feet (24 to 30 m) in height and 4.5 to 6.5 feet (1.2 to 2 m) in diameter. It prefers well-drained soil that is very deep and rich in nutrients, and it is very sensitive to conditions that are not ideal.
The species Nothofagus truncata, also known as the hard beech, is very similar to the red beech, but its trunk is more slender, and it tends to grow further north than other species. Another major difference is its ability to grow in much poorer conditions. This species of the Nothofagus genus can better tolerate poor soil and droughts.
Nothofagus plants have been growing in South America and Australia for more than 60 million years. The plants did not make it far north until humans helped them out, though birds could spread the seeds some ways. Over the years, there was some confusion over the relation between southern beeches and northern beeches, which belong to another genus; however, they are only very distant cousins.
A certain species, Nothofagus nuda, is reportedly responsible for nearly 1,000 deaths in the early 1900s. In Papua New Guinea, the plant was traditionally used as an herb in culinary dishes. Large doses makes one go into hypoglycemia shock, a state produced by extremely low blood sugar that can result in brain damage and death. Supposedly wives in polygamous tribes would use Nothofagus nuda to poison patriarchs during conflicts. As of 2010, the plant is threatened by habitat loss.
Remains of southern beeches were discovered in Antarctica, leading researchers to believe they were once very abundant in the area. Studies suggest the plants were small shrubs whose leaves fell during fall. These plants could have thrived as recently as two million years ago, meaning the environment of Antarctica may have been habitable a shorter time ago than previously thought.