Blechnum magellanicum
Remnants from a bygone era ( The Carboniferous Age: 358.9 - 298.9 mya ) before the rise of seed-bearing plants, the group collectively referred to as 'Tree Ferns' are the world's most primitive extant trees, reproducing using spores. Information about them is more scarce than better known groups which they superficially resemble, such as trees from the family, Arecaceae - the Palm Trees. One way to get a positive ID on Tree Ferns is to ascertain whether or not the tree in question has curled croziers emerging from its crown - if the tree has them, then it is a Tree Fern. The current convention in academia apparently stipulates that only the genera Cyathea, Dicksonia, Metaxyaceae and Cibotiaceae can be considered true Tree Ferns for some reason - possibly because it is believed that the former radiated out at an earlier point in geologic time. Tree Ferns will only grow in places where moisture is abundant, typically growing as a small understory tree under the protection of a sheltered forest canopy. Blechnum, which is a more obscure genus is considered an outlier. Like the 'proper' Tree Ferns of the aforementioned genera, it too has achieved arborescent form in some species. The species Blechnum magellanicum ( aka "Lomariocycas magellanicum" or simply the "Palmilla" ) is of particular interest because it inhabits the frigid coastal forests of Chile and Argentina from Talca at 35 degrees South to the Magallanes Region and into the humid valleys of Western Argentina close to the Chilean border. The species matures at around 1.5m tall and has large arching fronds that may exceed 1.8m long. It has been grown in the UK but is unfortunately extremely rare in cultivation. It is believed based on its native habitat that it can survive temperatures as low as -11.1 degrees Celsius and possibly even well below this temperature! It is believed to be ideally suited to a cool maritime climate. Instead of planting Livistona Palms in the UK and in the American Pacific Northwest, people should start planting these instead if this data holds true. I hope that Tree Ferns as a whole start receiving more attention in the future.