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pierre laszlo

 
Phylica

This plant, or rather tree, is one of the wonders of natural history. Small, perhaps better called a shrub, it boasts attractive narrow needle-like dark green leaves, downy silver on the underside, and greenish white terminal flowers. Amsterdam Island, part of Terres Aus-trales et Antarctiques Françaises, lies in the Southern Atlantic, relatively close to Antarctica, at a latitude of 37°50 S. This inhospitable piece of land is covered mostly with grassy plants, with one exception: Phylica nitida, also known as Phylica arborea, a tree from the Rhamnaceae, the buckthorn family. Phylica is a survivor. At one time it covered a quarter of the area of the island, but grazing cows have eaten it to the ground. Nowadays, it occu-pies 0.2 % of the total area, only because scientists replanted it behind a protective barrier of cypresses.
Phylica is found on another island in the South Atlantic, Gough Island (aka  Gonçalo Álvares), 220 miles to the SSE  of the Tristan da Cunha archipelago, at a latitude of 40.32° S. How did those trees get to Amsterdam and Gough? British botanists have elucidated their lineage. P. arborea on Amsterdam Island was derived from a single colonization of P. arborea from Gough Island. Similarly, the Gough Island population appears to have been derived from a single colonization event, but it is so distinct from those on Tristan da Cunha, that there may have been two separate dispersals to Gough and Nightingale Island (part of Tristan da Cunha) from different lines of the mainland progenitor. There is also evidence of a recolonization from Gough to Tristan da Cunha. Thus, Phylica arborea is capable of repeated long distance dispersal, up to 8000 km, even though the fruits and seeds are not of a type normally associated with this phenomenon. As for the means of dispersal over thousands of miles, it is conjectured that the yellow beak albatross, Diomedea chlororhynchos, transported the seeds.