Weeds of golf courses on the island of Tenerife.
We determine the biodiversity of weeds in four golf courses in Tenerife, two located in the North and two in the South. The total of 126 taxa was found in the South and 204 in the north, both being alien to 99%. Pennisetum clandestinum on the golf course The Rock (North of Tenerife) and Paspalum vaginatum in Costa Adeje Golf (Tenerife South) showed a high degree of invasion, with coverage of 60 and 45% respectively. Invasive alien common in the four fields are: Amaranthus blitum, Anagallis arvensis, Aster squamatus, Bromus catharticus, Conyza bonariensis Cronquist, C. floribunda, Oxalis corniculata, Paspalum vaginatum, Pennisetum clandestinum, Poa annua, Portulaca oleracea, Setaria adhaerens Sonchus oleraceus. Five new species are cited for Tenerife and the archipelago, Arctotheca calendula (Asteraceae), Amaranthus albus L. (Amaranthaceae), Chenopodium glaucus (Chenopodiaceae), Killing brevifolius and Pycreus mundtii (Cyperaceae). The golf courses in the North have more invasive alien species to the South, probably as a result of better water balance and also for their greater antiquity. The conclusion is that both are an important route of entry of exotic and also act as a reservoir of invasive plants.